Back contact battery assembly and photovoltaic system

Abstract

The utility model is suitable for the field of photovoltaic technology, and provides a back contact battery assembly and a photovoltaic system, and the back contact battery assembly comprises a battery string which at least comprises a first battery piece and a second battery piece which are sequentially arranged along a first direction, the first battery piece is arranged at the end part of the battery string, and the second battery piece is arranged at the end part of the battery string. The first welding strip is arranged on the backlight surface of the first battery piece; the second welding strip is arranged on the backlight surface of the second battery piece; the first bus bar is arranged on the backlight face of the second battery piece, the first bus bar can be arranged on the backlight face of the battery piece in a hidden mode, the effective light receiving area of the battery assembly can be increased, the conversion efficiency of the assembly can be improved, and the overall attractiveness of the battery assembly is better; moreover, the first bus bar is arranged on the second battery piece, so that the first welding strip can be ensured to be fully attached to and welded to the effective welding position of the first battery piece.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of photovoltaic technology, and particularly relates to a back contact cell module and a photovoltaic system. BACKGROUND

[0002] In the existing back contact cell module, the series connection bus bar between adjacent series connection cell strings is usually placed at the edge of the cell module, and the parallel connection bus bar between adjacent parallel connection cell strings is usually placed in the reserved interval area between two cell strings, which results in that a certain space needs to be reserved at the edge of the cell module for placing the series connection bus bar, and a certain space also needs to be reserved between two parallel connection cell strings for placing the parallel connection bus bar, which reduces the effective light receiving area of the cell module, affects the conversion efficiency of the module, and affects the appearance of the module.

[0003] In some products, the bus bar is installed at the middle position of the back surface of the cell piece, and an insulating strip is arranged between the bus bar and the cell piece. Although this arrangement mode can hide the bus bar, the insulating strip needs to be processed by punching to enable the bus bar to be in contact with the same polarity solder strip on the cell piece and to be insulated from the reverse polarity solder strip on the cell piece. This arrangement mode has high requirements for the punching precision of the insulating strip and the arrangement position precision of the insulating strip, and is difficult to produce, and is prone to short circuit or false welding due to position deviation of the insulating strip during punching. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a back contact cell module, which aims to solve the problems that the existing insulating strip needs to be processed by punching, has high requirements for the punching precision of the insulating strip and the arrangement position precision of the insulating strip, is difficult to produce, and is prone to short circuit or false welding due to position deviation of the insulating strip during punching.

[0005] The present application is implemented in the following manner. A back contact cell module comprises a cell string, the cell string at least comprising a first cell piece and a second cell piece arranged in sequence along a first direction, the first cell piece being arranged at the end of the cell string, a first solder strip, the first solder strip being arranged on the back surface of the first cell piece, a second solder strip, the second solder strip being arranged on the back surface of the second cell piece, a first bus bar, the first bus bar being arranged on the back surface of the second cell piece, and a first insulating strip, the first insulating strip being arranged between the first bus bar and the second cell piece, the first insulating strip being used for insulating the second solder strip and the first bus bar, the first insulating strip and the first bus bar being arranged in extension along a second direction, the first direction and the second direction being arranged in intersection, wherein the first solder strip and the second solder strip are arranged in parallel and in interval along the second direction, the first solder strip has an extension part extending to the second cell piece along the first direction, and the extension part is electrically connected with the first bus bar.

[0006] Optionally, the interval distance of the first solder strip and the second solder strip satisfies: 1mm≤L1≤1 / 2D, wherein L1 is the interval distance of the first solder strip and the second solder strip in the second direction, and D is the interval between two adjacent second solder strips.

[0007] Optionally, the back contact battery assembly further comprises a third solder strip, which extends from the first cell sheet to the second cell sheet along the first direction, and connects the first cell sheet and the second cell sheet.

[0008] Optionally, the third solder strips and the first solder strips are alternately arranged at intervals on the first cell sheet, and the second solder strips and the third solder strips are alternately arranged at intervals on the second cell sheet.

[0009] Optionally, the interval distance of the first solder strip and the second solder strip satisfies: 1mm≤L1≤1 / 2d, wherein L1 is the interval distance of the first solder strip and the second solder strip in the second direction, and d is the interval between two adjacent second solder strips and third solder strips.

[0010] Optionally, the first cell sheet and the second cell sheet are arranged on the same plane, and the first cell sheet and the second cell sheet are arranged at intervals.

[0011] Optionally, the interval distance of the first cell sheet and the second cell sheet is greater than or equal to 0 and less than or equal to 3mm.

[0012] Optionally, the first cell sheet and the second cell sheet are arranged to partially overlap in the first direction.

[0013] Optionally, the partially overlapping distance of the first cell sheet and the second cell sheet is greater than 0 and less than or equal to 1.5mm.

[0014] Optionally, the first cell sheet is provided with a first soldering point near one end of the second cell sheet, and the first soldering point is connected with the first solder strip.

[0015] Optionally, the first bus bar is arranged at the end of the second cell sheet close to the first cell sheet.

[0016] Optionally, the back contact battery assembly comprises at least two groups of cell strings arranged adjacent to each other in the second direction, and the first insulating strip extends from one of the two groups of cell strings to the other group of cell strings in the second direction.

[0017] The first bus bar can be hidden on the back surface of the battery piece, so that the effective light receiving area of the battery assembly can be increased, the conversion efficiency of the battery assembly can be improved, and the overall appearance of the battery assembly is better. In addition, since the first bus bar is arranged on the second battery piece, the first solder strip can be fully matched and welded with the effective welding position of the first battery piece, so that the welding of the first solder strip and the first battery piece is not insufficient due to the arrangement of the first bus bar, and the collection of current is affected. When assembling, the first insulating strip is arranged between the second battery piece and the first bus bar to isolate, the first insulating strip does not need to be punched, and does not need to be arranged discontinuously, which greatly simplifies the processing and installation process of the first insulating strip. In addition, in the second direction, the first solder strip and the second solder strip are arranged in a staggered and spaced manner to disperse the laminated pressure, so that the risk of battery piece cracking and fragmentation is reduced, and the reliability of the back contact battery assembly is good. In addition, the first solder strip has an extension portion extending to the second battery piece along the first direction, and the extension portion is electrically connected with the first bus bar, so as to realize the current collection of the carriers on the first battery piece.

[0018] A photovoltaic system comprising the back contact battery assembly. The technical effects of the present application are the same as those of the back contact battery assembly, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of a first back contact battery assembly provided by the present application;

[0020] Figure 2 is Figure 1 is an enlarged structural schematic diagram of the structure at A of

[0021] Figure 3 is a structural sectional view of the first back contact battery assembly provided by the present application;

[0022] Figure 4 is a structural sectional view of a second back contact battery assembly provided by the present application;

[0023] Figure 5 is a structural schematic diagram of a third back contact battery assembly provided by the present application.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] 100, battery string; 101, first battery piece; 102, second battery piece; 200, first solder strip; 201, extension portion; 300, second solder strip; 400, first bus bar; 500, first insulating strip; 600, third solder strip; 700, first solder joint. DETAILED DESCRIPTION

[0026] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein identical or similar labels denote identical or similar elements or elements having identical or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only and are merely intended to explain the present application, and are not to be understood as limiting the present application. In addition, it should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application.

[0027] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. 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 "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0029] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or 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 present application can be understood according to the specific circumstances.

[0030] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include the vertical direction of the first feature above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include the vertical direction of the first feature below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0031] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the elements and arrangements of the particular examples are described in the following disclosure. Of course, they are only examples and are not intended to limit the present application. Furthermore, the present application can repeatedly refer to reference numerals and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the application of other processes and / or the use of other materials.

[0032] As shown in the drawings, Figure 1 In the embodiment of the present application, a back contact battery assembly includes a battery string 100, and the battery string 100 at least includes a first battery piece 101 and a second battery piece 102 arranged in sequence along a first direction. It can be understood that in the battery string 100, the battery string 100 can include two battery pieces in series, three battery pieces in series, or more battery pieces in series, and the number of battery pieces in series can be determined according to actual use, and the present application does not limit this. In addition, the grid lines on the battery pieces are not shown in the drawings, and the grid lines on the battery pieces can be arranged according to actual conditions, for example, the battery pieces can be main grid battery pieces, or the battery pieces can be main grid-free battery pieces. It can be understood that when the battery pieces are main grid battery pieces, a first main grid line is arranged at a position corresponding to the first solder strip on the first battery piece, and a second main grid line is arranged at a position corresponding to the second solder strip on the second battery piece; when the battery pieces are main grid-free battery pieces, a welding point can be arranged at a position corresponding to the first solder strip on the first battery piece, and a welding point can be arranged at a position corresponding to the second solder strip on the second battery piece.

[0033] The first battery piece 101 is arranged at the end of the battery string 100. For the purpose of illustration, in the embodiment, the end where the first battery piece 101 is arranged is referred to as the tail end of the battery string 100, that is, in the first direction, the first battery piece 101 is the last battery piece of the battery string 100, and the second battery piece 102 is the second last battery piece of the battery string 100. It can be understood that the end where the first battery piece 101 is arranged can also be referred to as the head end of the battery string 100, and then the second battery piece 102 is the second battery piece of the battery string 100, and this will not be described in detail here.

[0034] It should be noted that when the first battery piece 101 is arranged at the tail end of the battery string 100, at this time, the first bus bar 400 can be used for series connection between adjacent battery strings 100 in the second direction; when the first battery piece 101 is arranged at the head end of the battery string 100, at this time, the first bus bar 400 can be used for parallel connection between adjacent battery strings 100 in the first direction, and at this time the first bus bar is equivalent to the middle bus bar in the battery assembly.

[0035] like Figure 3 As shown, in some embodiments, a first solder ribbon 200 is disposed on the backlight surface of the first battery cell 101, a second solder ribbon 300 is disposed on the backlight surface of the second battery cell 102, a first busbar 400 is disposed on the backlight surface of the second battery cell 102, and a first insulating strip 500 is disposed between the first busbar 400 and the second battery cell 102. The first insulating strip 500 is used to isolate the second solder ribbon 300 and the first busbar 400. Both the first insulating strip 500 and the first busbar 400 extend along a second direction, and the first direction and the second direction are intersected. Firstly, in this embodiment, the first busbar 400 is disposed on the second battery cell 102, and the first busbar 400 and the second battery cell 102 are separated by a first insulating strip 500. On the one hand, the edge of the back contact battery assembly no longer needs to reserve space for placing the busbar, and the battery assembly can reserve more space to install the battery cell, so that the effective light-receiving area of ​​the battery assembly is larger and the conversion efficiency of the assembly is higher. On the other hand, when viewed from the light-receiving surface (or "front") of the battery cell, the first insulating strip 500 can block the first busbar 400, preventing the first busbar 400 from being exposed, and the overall aesthetics of the battery assembly are better.

[0036] Secondly, compared to when the first busbar 400 is placed on the back of the first battery cell 101, as a possible scenario, the first solder strip 200 cannot be soldered to the first battery cell 101 at the position covered by the first busbar 400, resulting in insufficient soldering between the first solder strip 200 and the first battery cell 101 and poor current collection. In this embodiment, the first busbar 400 is disposed on the backlight surface of the second battery cell 102. The first solder ribbon 200 can fully adhere to and weld with the effective welding position of the first battery cell 101, avoiding insufficient welding between the first solder ribbon 200 and the first battery cell 101 due to the installation of the first busbar 400, which would affect the current collection. At the same time, after the first solder ribbon 200 is welded to the first battery cell 101, it can be directly connected to the first busbar 400 without the need to open holes in the insulating strip. During assembly, only the first insulating strip 500 needs to be placed on the second battery cell 102 as a whole, which effectively reduces the production precision requirements and production difficulty, avoids short circuits caused by positional displacement when opening holes in the insulating strip, and increases product yield. Preferably, the first busbar 400 is disposed at the end of the second battery cell 102 near the first battery cell 101. In this way, the extension portion 201 can be electrically connected to the first busbar 400 by extending to the edge of the second battery cell 102 near the first battery cell 101. This can reduce the extension length of the extension portion 201 of the first solder ribbon 200, save solder ribbon material, and thus reduce costs. Since the first solder ribbon 200 needs to be isolated from the second battery cell 102, the width requirement of the first insulating strip 500 is also reduced. The first insulating strip 500 only needs to insulate the edge area of ​​the second battery cell 102.

[0037] In this embodiment of the application, the first direction is the horizontal direction, which is also the width direction of the battery cell, and the second direction is the vertical direction, which is also the length direction of the battery cell. The first direction and the second direction are perpendicular to each other.

[0038] like Figure 2 As shown in the embodiment of this application, the first solder strip 200 and the second solder strip 300 are arranged parallel to each other in the second direction. The first solder strip has an extension portion extending to the second battery cell along the first direction, and the extension portion 201 is electrically connected to the first busbar. That is, the first solder strip 200 and the second solder strip 300 are staggered in the second direction, so that the extension portion 201 extending to the second battery cell 102 does not overlap with the second solder strip 300 on the second battery cell 102 in the length direction of the first busbar 400. This avoids the problem of excessive stress caused by the partial overlap of the extension portion 201 and the second solder strip 300 on the first busbar 400, and reduces the risk of microcracks in the battery cell during the lamination process.

[0039] This application allows the first busbar to be concealed on the back surface of the battery cell, increasing the effective light-receiving area of ​​the battery module, improving the module's conversion efficiency, and enhancing the overall aesthetics of the battery module. Furthermore, since the first busbar is located on the second battery cell, it ensures that the first solder strip can fully adhere to and weld with the effective welding position of the first battery cell, avoiding insufficient welding between the first solder strip and the first battery cell that would affect current collection. During assembly, a first insulating strip is placed between the second battery cell and the first busbar for isolation. The first insulating strip does not require holes or arrangement, greatly simplifying the processing and installation process of the first insulating strip. At the same time, in the second direction, by staggering the first solder strip and the second solder strip, the stacking height is reduced, and the stress during lamination is smaller, which can reduce the risk of microcracks and fragmentation of the battery cell, resulting in better reliability of the back-contact battery module. The first solder strip has an extension portion extending along the first direction to the second battery cell, and the extension portion is electrically connected to the first busbar to achieve current collection of charge carriers on the first battery cell.

[0040] like Figure 2As shown, in other embodiments, the first insulating strip 500 is arranged between the first bus bar 400 and the second cell 102, and the first insulating strip 500 is used to isolate the second solder strip 300 and the first bus bar 400. Since the first solder strip 200 has an extension part 201 extending to the second cell 102, it is understood that the first insulating strip 500 is also used to isolate the extension part 201 of the first solder strip 200 and the second cell 102. Specifically, the first insulating strip 500 can be arranged at the end of the second cell 102 close to the first cell 101. Optionally, the first insulating strip 500 can cover the edges of the second cell 102 and the first cell 101. In this way, on the one hand, it allows the first insulating strip 500 to have a certain degree of deviation in the width direction during the preparation process relative to the first bus bar 400 and the first insulating strip 500 relative to the two cells, which reduces the production precision requirement and production difficulty. On the other hand, it can avoid the short circuit caused by the contact between the first bus bar 400 and the female solder strip / female grid line on the first cell 101, and also avoid the short circuit caused by the contact between the first solder strip 200 and the female solder strip / female grid line of the second cell 102, as well as the short circuit caused by the conductive foreign matter such as tin slag during the preparation process, further reducing the risk of short circuit and improving the reliability of the battery assembly.

[0041] On the contrary, the first solder strip 200 in the embodiment of the present application can be applied to both the main grid back contact battery assembly and the main grid back contact battery assembly, and has stronger universality. Moreover, the first bus bar 400 is arranged at the end of the second cell 102 close to the first cell 101, which is smaller than the outer edge of the first cell 101, and has smaller stress during lamination, which can reduce the risk of fragmentation and cracking, and further improve the reliability of the battery assembly.

[0042] For example, the thickness of the first bus bar 400 can be between 0.06 mm and 0.3 mm, and the width can be between 8 mm and 20 mm. The material of the first bus bar 400 can be a tin-plated copper bus bar, a conductive copper foil, or an aluminum-based copper strip.

[0043] For example, the first insulating strip 500 can be an insulating glue, or a non-conductive adhesive tape or an insulating film, such as a PET or PI adhesive tape with acrylic or silicone, or a PET or PI substrate with a single-sided or double-sided film of ethylene-vinyl acetate copolymer or hot melt adhesive. It is understood that the first insulating strip 500 can include ethylene-vinyl acetate copolymer, resin material, polyimide, or polypropylene or polyethylene material, and can also include an acrylic adhesive layer.

[0044] It should be noted that the thickness of the first insulating strip 500 cannot be too thick or too thin. If the first insulating strip 500 is too thin, it is inconvenient to operate when pasting, and it is easy to deform when pulling. Long-term insulation also has the risk of damage. If it is too thick, it will increase the height difference, the stress generated during the lamination process will be large, and it is easy to cause fragmentation and increase the risk of false welding. Based on this, in the embodiments of the present application, the thickness of the first insulating strip 500 can be set to between 0.05 mm and 0.8 mm. In this way, the first insulating strip 500 will neither be too thin nor too thick. For example, the thickness of the first insulating strip 500 can be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm.

[0045] The width of the first insulating strip 500 is greater than or equal to the width of the first bus bar 400. If the width of the first insulating strip 500 is too narrow, the first bus bar 400 will be exposed, and there is a risk of short circuiting between the first bus bar 400 and the female electrode area or the female solder strip.

[0046] Further, the first solder strip 200 is a plurality of first solder strips 200, and the plurality of first solder strips 200 are arranged at the back light surface of the first battery piece 101 along the second direction. The second solder strip 300 is a plurality of second solder strips 300, and the plurality of second solder strips 300 are arranged at the back light surface of the second battery piece 102 along the second direction. The plurality of first solder strips 200 and the plurality of second solder strips 300 are arranged one by one.

[0047] In some embodiments, the first solder strip 200 and the second solder strip 300 are arranged in parallel. In this way, the first solder strip 200 and the second solder strip 300 can be independent of each other in the extension direction, so that even if the length of the first solder strip is relatively long, the extension part 201 of the first solder strip and the second solder strip 300 can be arranged separately and dispersedly without overlapping in the length direction of the first bus bar 400, so as to avoid the local stress concentration of the assembly and the hidden cracks of the battery piece. Preferably, the interval distance between the first solder strip 200 and the second solder strip 300 satisfies: 1mm≤L1≤1 / 2D, wherein L1 is the interval distance between the first solder strip 200 and the second solder strip 300 in the second direction, and D is the interval distance between adjacent two second solder strips 300. When the interval distance between the first solder strip 200 and the second solder strip 300 is within this range, it can be fully ensured that the first solder strip 200 and the second solder strip 300 do not overlap completely or overlap completely in the length direction of the first bus bar 400, so as to achieve the effect of dispersing the local stress of the battery assembly.

[0048] In some embodiments, the first battery piece 101 and the second battery piece 102 are arranged on the same plane, and the first battery piece 101 and the second battery piece 102 are arranged at intervals. In this way, there is a buffer space between each battery piece, so that each battery piece will not be damaged by mutual contact under the influence of external force on the battery assembly.

[0049] Specifically, the interval distance between the first cell tab 101 and the second cell tab 102 is greater than or equal to 0 and less than or equal to 3 mm. In such embodiments, the interval distance between the first cell tab 101 and the second cell tab 102 can be 0 mm, 1 mm, 2 mm, 3 mm, or any value between 0 and 3 mm, which is not limited herein. Within this range, while reducing the risk of tabbing of the cell tabs, the overall length of the battery string 100 is also prevented from being too long, improving the stability of the connection of adjacent cell tabs.

[0050] In some embodiments, the first cell tab 101 and the second cell tab 102 are arranged partially overlapping in the first direction. The contact area between the overlapping is not conductively connected, that is, no conductive adhesive or other adhesive is needed between the overlapping area, and the cell tabs are simply overlapped together. In this way, there is no gap between the first cell tab 101 and the second cell tab 102, so that the series welding band can be better hidden, and there is no need to set a shielding insulation layer in the gap between the cell tabs to hide the series welding band, thereby reducing the use of the shielding insulation layer, reducing production costs, and making it easier to repair. In addition, by overlapping the cell tabs, the size of the battery string 100 can be reduced, thereby making the battery string 100 occupy less space. Or, in the case of a certain size of the battery string 100, more cell tabs can be placed, improving the power of the battery string 100 and reducing the cost per watt. Preferably, the partially overlapping distance between the first cell tab 101 and the second cell tab 102 is greater than 0 and less than or equal to 1.5 mm. Exemplarily, the overlapping width range can be 0 mm, 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 1 mm, or 1.5 mm, which is not limited herein.

[0051] As Figure 4As shown, the back contact battery assembly further comprises a third solder strip 600, the third solder strip 600 extends from the first cell tab 101 to the second cell tab 102 along the first direction, and the third solder strip 600 connects the first cell tab 101 and the second cell tab 102. Specifically, a part of the third solder strip 600 is arranged on the first cell tab 101, and another part of the third solder strip 600 is arranged on the second cell tab 102. Exemplarily, the third solder strip 600 can be used to realize the series connection between the first cell tab 101 and the second cell tab 102. It can be understood that the first solder strip and the third solder strip are arranged on a part of the first cell tab without overlapping, and the second solder strip and the third solder strip 600 are arranged on another part of the second cell tab 102 without overlapping. In the length direction of the first bus bar 400, the first solder strip, the second solder strip and the third solder strip are independently spaced apart and arranged in parallel with each other, so as to realize the effect of local stress dispersion of the battery assembly. Further, the part of the third solder strip 600 on the second cell tab 102 is isolated by the first insulating strip 500 and the first bus bar 400. In the embodiment of the present application, the plurality of third solder strips and the plurality of first solder strips are alternately arranged on the first cell tab, and the plurality of second solder strips and the plurality of third solder strips are alternately arranged on the second cell tab. The plurality of solder strips are alternately arranged on the cell tab, which can form more current transmission paths, so as to improve the current transmission capacity of the battery assembly, so as to realize the uniform distribution of current on the cell tab.

[0052] In some embodiments, the interval distance between the first solder strip and the second solder strip satisfies: 1mm≤L1≤1 / 2d, where L1 is the interval distance between the first solder strip and the second solder strip in the second direction, and d is the interval between adjacent second solder strips and third solder strips. When the interval distance between the first solder strip 200 and the second solder strip 300 is within this range, it can be fully ensured that the first solder strip 200, the second solder strip 300 and the third solder strip 600 do not completely coincide or overlap in the length direction of the first bus bar 400, so as to realize the effect of local stress dispersion of the battery assembly.

[0053] In some embodiments, the first cell tab 101 is provided with a first soldering point 700 close to one end of the second cell tab 102, and the first soldering point 700 is connected with the first solder strip 200. It can be understood that the first soldering point 700 is located at the edge of the first cell tab 101 closest to the second cell tab 102 (i.e. the connection point of the most edge of the first solder strip 200 on the first cell tab 101), and the first soldering point 700 can be a grid line or a solder pad, so as to realize sufficient collection of charge carriers on the first cell tab, and improve the stability of the connection between the first solder strip 200 and the first cell tab 101.

[0054] As Figure 5As shown, in some embodiments, the back contact battery assembly at least includes two groups of battery strings 100 arranged adjacent to each other along the second direction, and the first insulation strip 500 extends from one of the two groups of battery strings to the other one of the two groups of battery strings along the second direction. In this way, the first insulation strip 500 can be laid once and for all between at least two adjacent groups of battery strings, simplifying the assembly steps of the battery assembly and improving the production efficiency of the battery assembly.

[0055] A photovoltaic system including the back contact battery assembly as described above. It can be understood that the photovoltaic power generation system includes at least one back contact battery assembly as described above, and it can be understood that the back contact battery assemblies can be electrically connected in parallel or in series, which can be selected and arranged according to actual needs. In the present embodiment, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc., and can also be applied in a device or apparatus that utilizes solar energy to generate electricity, such as a user solar power source, a solar street lamp, a solar car, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that need to utilize solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a combiner box, and an inverter, the photovoltaic array can be an array combination of a plurality of battery assemblies, for example, a plurality of battery assemblies can form a plurality of photovoltaic arrays, the photovoltaic arrays are connected to the combiner box, the combiner box can combine the currents generated by the photovoltaic arrays, the combined current flows through the inverter to convert into alternating current required by the power grid, and then is connected to the power network to realize solar power supply.

[0056] In the description of the present specification, the description of the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" and the like 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 mean 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.

[0057] 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. A back-contact battery assembly, characterized in that, include: A battery string, comprising at least a first battery cell and a second battery cell arranged sequentially along a first direction, the first battery cell being disposed at an end of the battery string; a first solder strip disposed on the backlight surface of the first battery cell; a second solder strip disposed on the backlight surface of the second battery cell; a first busbar disposed on the backlight surface of the second battery cell; and a first insulating strip disposed between the first busbar and the second battery cell, the first insulating strip being used to isolate the second solder strip and the first busbar. Both the first insulating strip and the first busbar extend along a second direction, the first direction intersecting the second direction. The first solder strip and the second solder strip are arranged parallel and spaced apart along the second direction, the first solder strip having an extension portion extending along the first direction to the second battery cell, the extension portion being electrically connected to the first busbar.

2. The back contact battery assembly as described in claim 1, characterized in that, The spacing between the first solder strip and the second solder strip satisfies: 1mm≤L1≤1 / 2D, where L1 is the spacing between the first solder strip and the second solder strip in the second direction, and D is the spacing between two adjacent second solder strips.

3. The back contact battery assembly as described in claim 1, characterized in that, The back contact battery assembly also includes a third solder strip that extends from the first battery cell to the second battery cell along the first direction, and the third solder strip connects the first battery cell and the second battery cell.

4. The back contact battery assembly as described in claim 3, characterized in that, On the first solar cell, a plurality of third solder strips and a plurality of first solder strips are alternately arranged at intervals; on the second solar cell, a plurality of second solder strips and a plurality of third solder strips are alternately arranged at intervals.

5. The back contact battery assembly as described in claim 4, characterized in that, The spacing between the first solder strip and the second solder strip satisfies: 1mm≤L1≤1 / 2d, where L1 is the spacing between the first solder strip and the second solder strip in the second direction, and d is the spacing between adjacent second solder strips and third solder strips.

6. The back contact battery assembly as claimed in claim 1, characterized in that, The first battery cell and the second battery cell are disposed on the same plane and are spaced apart.

7. The back contact battery assembly as described in claim 6, characterized in that, The distance between the first battery cell and the second battery cell is greater than or equal to 0 and less than or equal to 3 mm.

8. The back contact battery assembly as claimed in claim 1, characterized in that, In the first direction, the first battery cell and the second battery cell are partially overlapped.

9. The back contact battery assembly as claimed in claim 8, characterized in that, The local overlap distance between the first and second battery cells is greater than 0 and less than or equal to 1.5 mm.

10. The back contact battery assembly as claimed in claim 1, characterized in that, A first solder joint is provided at one end of the first battery cell near the second battery cell, and the first solder joint is connected to the first solder strip.

11. The back contact battery assembly as claimed in claim 1, characterized in that, The first busbar is located at the end of the second battery cell near the first battery cell.

12. The back contact battery assembly as claimed in claim 1, characterized in that, The back contact battery assembly includes at least two sets of battery strings arranged adjacent to each other along the second direction, wherein the first insulating strip extends from one of the two sets of battery strings to the other of the two sets of battery strings along the second direction.

13. A photovoltaic system, characterized in that, Includes the back contact battery assembly as described in any one of claims 1-12.

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