Intermediate bus bar, battery assembly and photovoltaic system

Abstract

The utility model relates to the technical field of solar cells, and provides a middle bus bar, a cell module and a photovoltaic system, a groove is formed in a position, close to a first edge, of a bus body of the middle bus bar, and a lead part which is bent towards a first side relative to the bus body is connected to the side wall, close to the first edge, of the groove; the bus body includes an extension portion between the lead portion and the first edge. Therefore, the lead part is not positioned at the outermost edge of the middle bus bar, so that the risk of short circuit caused by lap joint of the lead part and an adjacent line is reduced. Meanwhile, through the special structural design, the edge end position of the middle bus bar can be prevented from being tilted in the laminating process, so that the welding reliability of the welding strip at the edge position and the middle bus bar is ensured.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to an intermediate busbar, a cell 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, laminated, and encapsulated to form a solar module. A solar module consists of multiple cell strings, and a central busbar is typically located in the middle of the module. This busbar is used to weld the solder strips of the cell strings on either side to connect the two strings in parallel. The central busbar connects to a junction box.

[0003] In related technologies, such as Figure 1 As shown, in order to draw the current from the parallel battery string, the end of the intermediate busbar 310 is bent to form a lead-out portion 311 for insertion into the junction box 300 on the back plate. However, in this technical solution, the lead-out portion 311 is formed by bending one end of the intermediate busbar 300. The lead-out portion 311 is located at the edge of the intermediate busbar 310, which easily leads to overlap between the lead-out portion 311 and adjacent lines (such as opposite polarity solder strips on adjacent battery strings) due to the small distance between them, causing a short circuit. At the same time, during the manufacturing process, since the lead-out portion 310 is formed by bending the end of the intermediate busbar 310, during the lamination process, in order to facilitate lamination, the lead-out portion 310 needs to be pressed down onto the back plate first. During the pressing process, the bending position of the intermediate busbar 310 is prone to warping, which can easily lead to poor soldering between the solder strip at the edge and the intermediate busbar, resulting in poor welding reliability. Utility Model Content

[0004] This application provides an intermediate busbar, a battery module, and a photovoltaic system.

[0005] This application is implemented as follows: the intermediate busbar in the embodiments of this application includes:

[0006] The intermediate busbar includes:

[0007] A manifold body, having opposing first and second sides in the thickness direction, and opposing first and second edges in the length direction, with a groove formed near the first edge; and

[0008] A lead portion is connected to a side wall of the groove near the first edge, and the lead portion is bent towards the first side relative to the body portion, the lead portion matches the shape of the groove, and the busbar body includes an extension between the lead portion and the first edge, the lead portion is used to connect with a junction box of a battery assembly.

[0009] In some embodiments, the extension has a length of 0.5mm-20mm.

[0010] In some embodiments, the extension has a length of 0.5mm-2.5mm.

[0011] In some embodiments, the lead portion has a width of less than 10mm.

[0012] In some embodiments, the lead portion has a length of 20mm-25mm.

[0013] In some embodiments, the lead portion includes a first portion connected to a side wall of the groove towards the first edge, and a second portion connected to the first portion, the second portion has a width smaller than that of the first portion, and the second portion is used to connect with a junction box of a battery assembly.

[0014] In some embodiments, the second portion has a width of less than 10mm; and / or

[0015] The second portion has a length of 12mm-18mm.

[0016] In some embodiments, the intermediate busbar further includes a folded portion connected at the first edge, the folded portion is bent towards the second side relative to the busbar body and stacked on the second side of the busbar body, and the folded portion covers at least a partial area of the groove.

[0017] The present application also provides a battery assembly, which includes:

[0018] Parallel battery string units, which include a first battery string and a second battery string arranged along a first direction, the first battery string and the second battery string each include a plurality of battery pieces connected in series along the first direction;

[0019] The intermediate busbar of any one of the above, which is used to connect the first battery string and the second battery string in parallel; and

[0020] A junction box, the lead portion is inserted into the junction box and electrically connected with the junction box.

[0021] The present application also provides a photovoltaic system, which includes the above battery assembly.

[0022] In the intermediate busbar, the battery assembly and the photovoltaic system provided in the embodiments of the present application, a groove is formed on the busbar body of the intermediate busbar at a position close to the first edge, a lead part is connected on the side wall of the groove close to the first edge and bent towards the first side relative to the busbar body, and the busbar body comprises an extension part between the lead part and the first edge. In this way, by forming the groove on the busbar body, the lead part is not located at the edge of the intermediate busbar by having the lead part on the side wall of the groove and the part of the busbar body between the lead part and the first edge having a preset length, so as to reduce the risk of short circuit caused by the lead part being overlapped with the adjacent line (such as the heteropolarity solder strip). Meanwhile, by such a special structure design, since the position where the lead part is bent relative to the busbar body is away from the edge of the intermediate busbar by a certain distance, even if the lead part needs to be first passed through the groove on the back plate and bent and pressed on the back plate during the lamination process, the force generated by bending the lead part can be offset by the parts of the busbar body on both sides of the lead part, so as to avoid the edge end position of the intermediate busbar being warped, thereby ensuring the welding reliability of the solder strip at the edge position and the intermediate busbar. In addition, the lead part is matched with the shape of the groove, so that the groove and the lead part can be directly formed by cutting the busbar and bending the cut part towards the first side, which can simplify the manufacturing process and save materials.

[0023] Additional aspects and advantages of the application will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a connection structure between the junction box and the intermediate busbar in the battery assembly in the related art;

[0025] Figure 2 is a module schematic diagram of the photovoltaic system provided in the embodiments of the present application;

[0026] Figure 3 is a planar schematic diagram of the battery assembly provided in the embodiments of the present application;

[0027] Figure 4 is Figure 3 is an enlarged schematic diagram of the battery assembly at IV in

[0028] Figure 5 is a cross-sectional structure schematic diagram of the intermediate busbar provided in the embodiments of the present application;

[0029] Figure 6 is another cross-sectional structure schematic diagram of the intermediate busbar provided in the embodiments of the present application;

[0030] Figure 7is a top view of the intermediate busbar provided by the embodiment of the present application;

[0031] Figure 8 is Figure 7 is a left view of the intermediate busbar in

[0032] Figure 9 is another top view of the intermediate busbar provided by the embodiment of the present application;

[0033] Figure 10 is Figure 9 is a left view of the intermediate busbar in

[0034] Figure 11 is still another sectional structure schematic view of the intermediate busbar provided by the embodiment of the present application.

[0035] Main element symbol explanation:

[0036] Photovoltaic system 1000, battery assembly 100, parallel battery string unit 10, first battery string 11, second battery string 12, battery piece 101, intermediate busbar 20, busbar body 21, lead wire part 22, folding part 23, junction box 30, first edge busbar 40, second edge busbar 50. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0038] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "lateral", "longitudinal" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0039] In addition, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0040] In the description of the application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0041] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0042] The following disclosure provides many different embodiments or examples for implementing different structures of the application. In order to simplify the disclosure of the application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the application. In addition, the application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0043] Please refer to Figure 2 and Figure 3 The photovoltaic system 1000 in the embodiment of the application can include the battery assembly 100 in the embodiment of the application, and the battery assembly 100 in the embodiment of the application can include a plurality of battery pieces 101. The battery piece 101 can be a back contact solar cell piece, or a Topcon solar cell piece, etc., and the specific type is not limited here.

[0044] In embodiments of the present application, a plurality of battery pieces 101 in the battery assembly 100 can be connected in series to form a plurality of battery strings, and each battery string can be connected in series and parallel to realize the current output, for example, the connection between each battery piece 101 can be realized by welding the welding strip, and the connection between each battery string in series and parallel can be realized by the intermediate busbar 20, the first edge busbar 40 and the second edge busbar 50 described below. Each battery string can form an array of battery pieces 101, and then be packaged together by the front plate, the front adhesive film, the rear adhesive film and the back plate to form the battery assembly 100.

[0045] Please refer to Figure 3 , the battery assembly 100 includes a plurality of battery strings, each of which includes a plurality of battery pieces 101 connected in series along a first direction. As Figure 3 indicated, the battery assembly 100 can include a plurality of parallel battery string units 10, and the parallel battery string unit 10 includes a first battery string 11 and a second battery string 12 arranged along the first direction, and the first battery string 11 and the second battery string 12 each include a plurality of battery pieces 101 connected in series along the first direction. In some embodiments, the first battery string 11 and the second battery string 12 can be symmetric about the center line of the battery assembly 100 in the first direction.

[0046] As Figure 3 and Figure 4 indicated, the battery assembly 100 further includes the intermediate busbar 20 and the junction box 30 in embodiments of the present application, the intermediate busbar 20 is used to connect the first battery string 11 and the second battery string 12 in parallel, that is, the first battery string 11 and the second battery string 12 are connected with the intermediate busbar 20, and the polarity of the first battery string 11 and the second battery string 12 connected with each other is the same. The junction box 30 is arranged on the back plate of the battery assembly 100, and the bypass diode is arranged in the junction box 30.

[0047] As Figure 3 indicated, in the battery assembly 100, the battery assembly 100 can have a plurality of parallel battery string units 10, and the plurality of parallel battery units are arranged along a second direction, and the first direction can be the longitudinal direction of the battery assembly 100, and the second direction can be the transverse direction of the battery assembly 100. In the plurality of parallel battery string units 10, adjacent first battery strings 11 are connected in series in pairs by the first edge busbar 40, and adjacent second battery strings 12 are connected in series in pairs by the second edge busbar 50.

[0048] Specifically, as Figure 3 indicated, Figure 3 indicates that the number of parallel battery string units 10 is 6, in which case, as Figure 3As shown in Figure 4, there are 3 first edge busbars 40, 3 second edge busbars 50, 4 intermediate busbars 20, and 3 junction boxes 30. A junction box 30 is provided between each pair of adjacent intermediate busbars 20. In each pair of adjacent intermediate busbars 20, one intermediate busbar 20 is connected to the positive terminal of the junction box 30, and the other is connected to the negative terminal of the junction box 30. Figure 4 As shown, in Figure 4 In the example shown, among the four intermediate busbars 20, the two intermediate busbars 20 located at the two edges in the second direction are short busbars, and the two intermediate busbars 20 located in the middle are long busbars. The short busbars are connected to the positive or negative terminal of a junction box 30 at only one end, while the long busbars are connected to the positive terminal of a junction box 30 at one end and to the negative terminal of another junction box 30 at the other end.

[0049] Please see Figure 5 In this embodiment, the intermediate busbar 20 may include a busbar body 21 and a lead portion 22. The busbar body 21 has opposing first and second sides in the thickness direction, and opposing first edge 211 and second edge 212 in the length direction. Figure 5 and Figure 6 As shown, a groove 210 is formed on the busbar body 21 near the first edge 211.

[0050] The lead portion 22 is connected to the sidewall of the recess 210 near the first edge 211, and the lead portion 22 is bent toward the first side relative to the busbar body 21. The shape of the lead portion 22 matches that of the recess 210, that is, when the lead portion 22 is bent toward the side where the second edge 212 is located until it is flush with the busbar body 21, the lead portion 22 fills the recess 210. The busbar body 21 includes an extension 213 located on the side where the lead portion 22 is located and the first edge 211 (i.e., the portion of the busbar body 21 located between the lead portion 22 and the first edge 210). The lead portion 22 is used to connect to the junction box 30 of the battery assembly 100.

[0051] Specifically, in the battery assembly 100, the lead wire 22 can pass through the back plate of the battery assembly 100 and be inserted into the junction box 30 to connect to the positive or negative terminal of the junction box 30.

[0052] In the parallel battery string unit 10, both the first battery string 11 and the second battery string 12 are connected in parallel with the bus body 21. Specifically, both the first battery string 11 and the second battery string 12 have several solder strips, and both can be soldered to the bus body 21 through the solder strips.

[0053] In the middle busbar 20, the battery assembly 100 and the photovoltaic system 1000 of the embodiments of the present application, the busbar body 21 of the middle busbar 20 is provided with a groove 210 at a position close to the first edge 211, the side wall of the groove 210 close to the first edge 210 is connected with a lead part 22 which is bent towards the first side relative to the busbar body 21, and the busbar body 21 comprises an extension part 213 between the lead part 22 and the first edge 211. In this way, by providing the groove 210 on the busbar body 21, the lead part 22 is provided on the side wall of the groove 210 and the busbar body 21 comprises the extension part 213 between the lead part 22 and the first edge 211, so that the lead part 22 is not located at the edge of the middle busbar 20, thereby reducing the risk of short circuit caused by the lead part being overlapped with the adjacent line (for example, the heteropolarity solder strip). At the same time, due to the special structure design, the position where the lead part 22 is bent relative to the busbar body 21 is away from the edge of the middle busbar 20, even if the lead part 22 needs to be first passed through the groove on the back plate and bent and pressed on the back plate during the lamination process, the force generated by bending the lead part 22 can be offset by the parts of the busbar body 21 on both sides of the lead part 22, so that the edge end position of the middle busbar 20 is prevented from being warped, thereby ensuring the welding reliability of the solder strip at the edge position and the middle busbar 20. In addition, the shape of the lead part 22 matches the shape of the groove 210, so that the groove 210 and the lead part 22 can be directly formed by cutting the busbar and bending the cut part towards the first side, which can simplify the manufacturing process and save materials.

[0054] Specifically, the middle busbar 20 is made of metal material, for example, aluminum strip, copper strip, tin strip, etc., which is not specifically limited herein. In some embodiments, the middle busbar 20 can be an integral structure, which can be formed by cutting a continuous and flat busbar and then bending it, for example, the busbar can be first cut by marking to obtain three edges of the groove 210, so that the busbar forms a bendable overhanging section at the cutting position, and then the overhanging section can be pressed towards the first side to bend the overhanging section towards the first side, thereby forming the groove 210 and the lead part 22 on the busbar. In the embodiments of the present application, the lead part 22 can be perpendicular to the busbar body 21.

[0055] Please refer to Figure 4 As shown above, in the middle busbar 20 of the battery assembly 100, the short busbar is connected with only one polarity of one junction box 30. Therefore, in the short busbar, the groove 210 and the lead part 22 can be provided only at the position of the busbar body 21 close to the first edge 211.

[0056] As Figure 4As shown, in the middle busbar 20 of the battery assembly 100, the long busbar needs to be connected with the ports of two different polarities of the terminal box 30. Therefore, in the long busbar, the recess 210 can also be formed at the position of the busbar body 21 close to the second edge 212, and another lead part 22 is also arranged, and the structure at the first edge 211 is symmetrical to the structure at the second edge 212, that is, the middle busbar 20 is symmetrical about the center line in the length direction. That is to say, the middle busbar 20 in the embodiment of the application can be that only the first edge 211 of the busbar body 21 has the recess 210 and the lead part 22, or the first edge 211 and the second edge 212 both have the recess 210 and the lead part 22.

[0057] As shown in FIG. 1, Figure 5 In some embodiments, the recess 210 can completely penetrate the busbar body 21 in the thickness direction. In this way, the lead part 22 can have the same thickness as the busbar body 210, thereby improving the current transmission capacity of the lead part 22.

[0058] Of course, as Figure 6 As shown, in some embodiments, the recess 210 can also not penetrate the busbar body 210, that is, the recess 210 can be regarded as a blind hole formed in the busbar body 210. In this way, the welding area of the solder strip at the position of the recess 210 can be effectively avoided from being too small due to the hollowing-out of the recess 210.

[0059] As shown in FIG. 1, Figure 5 and Figure 6 In some embodiments, the length L1 of the extension part 213 (the part of the busbar body 21 between the lead part 22 and the first edge 210) is 0.5 mm-20 mm. In this way, by setting the length of the part of the busbar body 21 between the lead part 22 and the first edge 210 in this reasonable range, it can be avoided that the length of the part is too long to cause short circuit due to the overlap with the adjacent line, and it can also be avoided that the length L1 of the part is too small to cause the solder strip at the edge to fail to form stable contact with the part.

[0060] Specifically, in such embodiments, the length L1 of the extension part 213 is preferably 0.5 mm-2 mm, for example, the length can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, or any value between 0.5 mm and 2 mm, which is not specifically limited here.

[0061] As shown in FIG. 1, Figure 7 and Figure 8 In some embodiments, the width D1 of the lead part 22 is less than 12 mm.

[0062] Thus, the width of the lead portion 22 is set smaller, so that the lead portion can be easily inserted into the connecting terminal of the terminal box 30. In some embodiments, the width D1 of the lead portion 22 is preferably less than 10 mm.

[0063] Further, in some embodiments, the width D2 of the busbar body 21 can be 10-15 mm.

[0064] Thus, the width of the busbar body 21 is set in the range of 10-15 mm, so that the welding stability of the welding strip and the busbar body 21 can be ensured while the busbar transmission loss and cost are controlled.

[0065] In some embodiments, the length L2 of the lead portion 22 is 15-35 mm. In some embodiments, the length of the lead portion 22 can be preferably 20-25 mm.

[0066] Thus, the length of the lead portion 22 can be avoided to be too short, so that the length of the portion of the lead portion inserted into the terminal box 30 is not too short, and the connection stability between the portion and the connecting terminal of the terminal box 30 is not poor.

[0067] Specifically, in such embodiments, the length L2 of the lead portion 22 can be, for example, 15 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, 35 mm, or any value between 15 mm and 35 mm. Preferably, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, or any value between 20 mm and 25 mm.

[0068] Please refer to Figure 9 and Figure 10 In some embodiments, the lead portion 22 comprises a first portion 221 and a second portion 222, the first portion 221 is connected to the side wall of the groove 210 towards the first edge 211, and the second portion 222 is connected to the first portion 221, the width D4 of the second portion 222 is smaller than the width D3 of the first portion 221, i.e., D4

[0069] Thus, the width of the first portion 221 is set wider, and the width of the second portion 222 is set narrower, so that the second portion 222 can be easily inserted into the terminal box 30 through the connection with the connecting terminal of the terminal box 30, and the material cost can be saved, and the first portion 221 is set wider, so that the transmission loss is reduced.

[0070] In some embodiments, the width D4 of the second portion 222 is less than 10 mm, preferably less than 9.6 mm. In this way, it can be ensured that the second portion 222 can be simply and smoothly inserted into the terminal box 30, avoiding that the width of the second portion 222 is too wide to cause difficulty in inserting the second portion 222 into the terminal box 30.

[0071] In some embodiments, the length L3 of the second portion 222 is 12-18 mm. In this way, it can be avoided that the length of the second portion 222 is too short to cause that the length of the second portion 222 extending from the back plate is too short to cause that the portion of the second portion 222 for insertion into the terminal box 30 is too short to cause unstable connection, and it can also be avoided that the length of the second portion 222 is too large to cause cost increase.

[0072] In particular, in such embodiments, the overall length of the lead portion 22 can be 15-35 mm, preferably 20-25 mm. The length of the second portion 222 is preferably 12-18 mm.

[0073] Please refer to Figure 11 In some embodiments, the intermediate busbar 20 can further comprise a folded portion 23 connected at the first edge 210, the folded portion 23 being bent towards the second side relative to the busbar body 21 and stacked on the second side of the busbar body 21, the folded portion 23 shielding at least part of the area of the groove 210.

[0074] In this way, when the groove 210 completely penetrates the busbar body 21, the provision of the folded portion 23 can make the intermediate busbar 20 also have a portion that can be used for welding at the position of the groove 210, avoiding poor welding at the position of the groove 210 during the process of welding the solder strip.

[0075] In particular, as Figure 11 shown, in such embodiments, the folded portion 23 can completely cover the groove 210.

[0076] In the description of the present specification, the description referring to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0077] In addition, the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An intermediate busbar for a battery assembly, characterized by, The intermediate busbar comprises: a busbar body having opposite first and second sides in a thickness direction, and opposite first and second edges in a length direction, the busbar body being formed with a groove at a position close to the first edge; and a lead portion connected to a side wall of the groove close to the first edge, and bent towards the first side relative to the body portion, the lead portion matching a shape of the groove, the busbar body comprising an extension between the lead portion and the first edge, the lead portion being configured to be connected to a junction box of a battery assembly.

2. The intermediate busbar of claim 1, wherein The groove completely penetrates the busbar body in the thickness direction.

3. The intermediate busbar of claim 1, wherein, The extension has a length of 0.5-20mm.

4. The intermediate busbar of claim 3, wherein, The extension has a length of 0.5-2.5mm.

5. The intermediate busbar of claim 1, wherein, The lead portion has a width of less than 10mm.

6. The intermediate busbar of claim 1, wherein, The lead portion has a length of 20-25mm.

7. The intermediate busbar of claim 1, wherein, The lead portion comprises a first portion connected to a side wall of the groove towards the first edge, and a second portion connected to the first portion, the second portion having a width less than that of the first portion, the second portion being configured to be connected to the junction box of the battery assembly.

8. The intermediate busbar of claim 7, wherein, The second portion has a width of less than 10mm; and / or The second portion has a length of 12-18mm.

9. The intermediate busbar of claim 2, wherein, The intermediate busbar further comprises a folded portion connected at the first edge, the folded portion being bent towards the second side relative to the busbar body and stacked on the second side of the busbar body, the folded portion shielding at least a part of the groove.

10. A battery assembly characterized by, comprises: parallel battery string units comprising first and second battery strings arranged along a first direction, each of the first and second battery strings comprising a plurality of battery cells arranged in series along the first direction; the intermediate busbar of any one of claims 1-9, the intermediate busbar being configured to connect the first and second battery strings in parallel; and a junction box into which the lead portion is inserted to be electrically connected to the junction box.

11. A photovoltaic system characterized by, comprises the battery assembly of claim 10.

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