Main-grid-free back contact battery piece, battery string, battery assembly and photovoltaic system
By using a gridless back-contact cell design and employing non-equidistant welding points and ribbons, the problems of high slurry loss and long carrier transport paths caused by grid use are solved, resulting in cost reduction and efficiency improvement.
Patent Information
- Application Number
- CN202520173673.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-06-12
- Filing Date
- 2025-01-24
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-01-24
AI Technical Summary
The use of a main grid in existing back-contact solar cells results in high paste loss, high cost, and long carrier transport path, leading to low efficiency.
The design employs a gridless back-contact cell structure. By alternately setting the first and second fine grids on the back of the silicon wafer, and directly setting non-equidistant welding points on them to weld with the solder ribbon, a cell string is formed, reducing the use of paste and optimizing the distribution of solder ribbon.
It reduces costs, improves carrier collection efficiency, enhances the overall efficiency of the solar cells, and simplifies the manufacturing process of solar cell modules.
Smart Images
Figure CN223859569U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of solar cells, in particular to a back contact cell without main grid, a cell string, a cell module and a photovoltaic system. BACKGROUND
[0002] Solar cell power generation is a sustainable clean energy source, which can convert sunlight into electricity by using the photovoltaic effect of semiconductor p-n junction. In a solar cell, a back contact solar cell is a cell in which the emitter and base contact electrodes are placed on the back surface (non-light receiving surface) of the cell. The light receiving surface of the cell has no metal electrode to block, thereby effectively increasing the short-circuit current of the cell.
[0003] In order to realize the series connection of the cell, the back surface of the back contact solar cell is provided with main grids of two polarities, and a cell string is formed by welding ribbons and the main grids. In the related art, the main grids of the two polarities are uniformly distributed on the back surface of the cell. However, in such a technical solution, the loss of paste is large when the main grid is used, and the cost is high. At the same time, the spacing between the main grids of the same polarity is large, the transmission path of the carriers is relatively far, and the efficiency is low. CONTENT OF THE UTILITY MODEL
[0004] The present application provides a back contact cell without main grid, a cell string, a cell module and a photovoltaic system.
[0005] The present application is implemented in this way. The back contact cell without main grid of the present application comprises:
[0006] A silicon wafer having opposite front and back surfaces;
[0007] A plurality of first fine grids and a plurality of second fine grids are arranged on the back surface in a first direction and extend in a second direction, and the second direction intersects the first direction.
[0008] The first fine grid has a plurality of first welding points for welding a first welding ribbon, and the distance between two adjacent first welding points on the same first fine grid is equal.
[0009] The second fine grid has a plurality of second welding points for welding a second welding ribbon, and the distance between two adjacent second welding points on the same second fine grid is equal.
[0010] In the second direction, a distance between an n-th first soldering point on the first fine grid and an n-th second soldering point on the second fine grid is a first distance, and a distance between the n-th second soldering point on the second fine grid and an n+1-th first soldering point on the first fine grid is a second distance, the first distance being different from the second distance, n being a positive integer.
[0011] Further, the silicon wafer has opposite first and second edges in the second direction, in which neither end of the first fine grid nor the second fine grid has a soldering point.
[0012] Further, the soldering point closest to the first edge is the first soldering point, and a distance between the first soldering point closest to the first edge and the first edge is 5-9 mm.
[0013] Further, the soldering point closest to the second edge is the first soldering point or the second soldering point, and a distance between the first soldering point or the second soldering point closest to the first edge and the second edge is 5-9 mm.
[0014] Further, the first distance is smaller than the second distance.
[0015] Further, the first distance is 4.5-6.5 mm in size.
[0016] Further, the second distance is 10.5-12.5 mm in size.
[0017] Further, on the first fine grid, a distance between two adjacent first soldering points is 15.5-19.5 mm.
[0018] Further, on the second fine grid, a distance between two adjacent second soldering points is 15.5-19.5 mm.
[0019] The application further provides a battery string comprising a plurality of the back contact battery piece without busbars as described in any one of the above, the plurality of the back contact battery piece without busbars being arranged at intervals in the first direction;
[0020] A plurality of first soldering bands and a plurality of second soldering bands are arranged on the back contact battery piece without busbars, the plurality of first soldering bands and the plurality of second soldering bands being arranged at intervals in the second direction alternately and sequentially and extending in the first direction, the first soldering bands being electrically connected to the first soldering points on the first fine grid and being insulated from the second fine grid, and the second soldering bands being electrically connected to the second soldering points on the second fine grid and being insulated from the first fine grid.
[0021] The first solder strip in the nth back contact cell without main grid is electrically connected with the second solder strip of the (n+1)th back contact cell without main grid, and the second solder strip in the nth back contact cell without main grid is electrically connected with the first solder strip of the (n+1)th back contact cell without main grid, n is a positive integer;
[0022] In the second direction, the distance between adjacent first solder strips in the back contact cell without main grid is equal, and the distance between adjacent second solder strips is also equal, the distance between the ith first solder strip and the ith second solder strip in the back contact cell without main grid is a third distance, the distance between the ith second solder strip and the (i+1)th first solder strip is a fourth distance, the third distance is different from the fourth distance, i is a positive integer.
[0023] Further, the silicon wafer has opposite first and second edges in the second direction, and in the back contact cell without main grid, the type of solder strip closest to the first edge is the first solder strip, and the distance between the first solder strip closest to the first edge and the first edge is 3-9 mm.
[0024] Further, the type of solder strip closest to the second edge is the first solder strip or the second solder strip, and the distance between the first solder strip or the second solder strip closest to the second edge and the second edge is 3-9 mm.
[0025] Further, the third distance is less than the fourth distance.
[0026] Further, the third distance is 2-4 mm in size;
[0027] The fourth distance is 8-10 mm in size.
[0028] Further, the distance between two adjacent first solder strips is 13-17 mm.
[0029] Further, the distance between two adjacent second solder strips is 13-17 mm.
[0030] The application also provides a battery assembly, comprising:
[0031] A first battery string, which is any of the above-mentioned battery strings;
[0032] A second battery string, which is obtained by rotating the first battery string by 180°, and the second battery string and the first battery string are arranged at intervals along the first direction; and
[0033] a first intermediate busbar disposed between the first and second strings of cells, the first intermediate busbar being electrically connected to a first tab on a cell in the first string of cells closest to the first intermediate busbar, and the first intermediate busbar also being electrically connected to a first tab on a cell in the second string of cells closest to the first intermediate busbar.
[0034] Further, the silicon wafer has opposite first and second edges in the second direction, and along the second direction, a tab on a cell in the first string of cells closest to the first intermediate busbar is electrically connected to the first intermediate busbar.
[0035] Further, the silicon wafer has opposite first and second edges in the second direction, and along the second direction, a tab on a cell in the first string of cells closest to the first intermediate busbar is electrically connected to the first intermediate busbar.
[0036] Further, the solar cell module further comprises a third string of cells, a fourth string of cells, and a second intermediate busbar, the third string of cells being obtained by rotating the first string of cells by 180°, and the fourth string of cells being identical to the first string of cells.
[0037] The third string of cells is spaced apart from the first string of cells along the second direction.
[0038] The fourth string of cells is spaced apart from the second string of cells along the second direction.
[0039] The third string of cells is spaced apart from the fourth string of cells along the first direction.
[0040] The second intermediate busbar is disposed between the third and fourth strings of cells, the second intermediate busbar being electrically connected to a second tab on a cell in the third string of cells closest to the second intermediate busbar, and the second intermediate busbar also being electrically connected to a second tab on a cell in the fourth string of cells closest to the second intermediate busbar.
[0041] Further, the silicon wafer has opposite first and second edges in the second direction, and along the second direction, a tab on a cell in the third string of cells closest to the second intermediate busbar is electrically connected to the second intermediate busbar.
[0042] Further, the silicon wafer has opposite first and second edges in the second direction, and along the second direction, a tab on a cell in the third string of cells closest to the second intermediate busbar is electrically connected to the second intermediate busbar.
[0043] The present application also provides a photovoltaic system, which comprises the solar cell module as described above.
[0044] In the back contact cell without main grid, the cell string, the cell module and the photovoltaic system in the embodiments of the present application, the first soldering point is directly arranged on the first fine grid and soldered with the first solder ribbon, and the second soldering point is directly arranged on the second fine grid and soldered with the second solder ribbon, so that the cell string is formed by soldering without arranging the main grid, the use of paste can be reduced, and the cost can be reduced. Meanwhile, in the second direction, the distance between the first soldering point on the first fine grid and the n th second soldering point on the second fine grid is the first distance, the distance between the n th second soldering point on the second fine grid and the n+1 th first soldering point on the first fine grid is the second distance, and the first distance is different from the second distance. In this way, the first solder ribbon and the second solder ribbon are distributed in a non-equidistant manner. In the case of the same size and the same number, compared with the traditional equidistant distribution scheme, the second solder ribbon can be relatively close to the first solder ribbon, and the distance between the adjacent two first solder ribbons and the distance between the adjacent two second solder ribbons can also be set to be relatively close, so that the collection efficiency of carriers is improved, and the efficiency of the cell is improved.
[0045] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description. BRIEF DESCRIPTION OF DRAWINGS
[0046] Figure 1 FIG. 1 is a schematic diagram of a module of a photovoltaic system provided by an embodiment of the present application.
[0047] Figure 2 FIG. 2 is a schematic diagram of the structure of a back contact cell without main grid provided by an embodiment of the present application.
[0048] Figure 3 FIG. 3 is a schematic diagram of the planar structure of a cell string provided by an embodiment of the present application.
[0049] Figure 4 FIG. 4 is a schematic diagram of part of the structure of a cell string provided by an embodiment of the present application.
[0050] Figure 5 FIG. 5 is a schematic diagram of the planar structure of a cell module provided by an embodiment of the present application.
[0051] MAIN ELEMENT SYMBOL EXPLANATION
[0052] Photovoltaic system 1000, cell module 200, cell string 100, back contact cell without main grid 10, silicon wafer 11, back surface 111, first edge 112, second edge 113, first fine grid 12, second fine grid 13, first solder ribbon 20, second solder ribbon 30, first cell string 210, second cell string 220, third cell string 230, fourth cell string 240, first intermediate busbar 260, second intermediate busbar 270, edge busbar 280. DETAILED DESCRIPTION
[0053] 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 the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. It should be noted that the embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and should not 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 should not be used to limit the present application.
[0054] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "transverse", "longitudinal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application.
[0055] In addition, the terms "first", "second" are only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. 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 "several" is two or more, unless otherwise explicitly specified and limited.
[0056] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "above", "over" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height. The "below", "under" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower than the second feature in horizontal height.
[0057] The disclosure below provides many different embodiments or examples for implementing different structures of the application. For the purpose of simplification of the present disclosure, certain examples are described in the following with reference to the components and arrangements thereof. Of course, they are merely examples and are not intended to limit the present application. Furthermore, reference numerals and / or letters are repeated in different examples in the following description for the purpose of simplicity and clarity, and such repetition is not to be understood to indicate that the various embodiments and / or arrangements discussed are related, unless otherwise noted. Moreover, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art can recognize that other processes can be applied and / or other materials can be used.
[0058] Referring to Figure 1 The photovoltaic system 1000 in the embodiments of the present application can include the battery assembly 200 in the embodiments of the present application, and the battery assembly 200 in the embodiments of the present application can include a plurality of the battery string 100 in the embodiments of the present application.
[0059] Referring to Figure 2 and Figure 4 The battery string 100 in the embodiments of the present application can include a plurality of the back contact cell 10 without busbars in the embodiments of the present application and a plurality of the first solder strip 20 and a plurality of the second solder strip 30 (only 3 are shown in the figure, and the number is not specifically limited in the present application).
[0060] Referring to Figure 2 and Figure 4 The back contact cell 10 without busbars in the embodiments of the present application can include a silicon wafer 11, a plurality of first fine grids 12, and a plurality of second fine grids 13.
[0061] The silicon wafer 11 has opposite front and back surfaces 111, and the plurality of first fine grids 12 and the plurality of second fine grids 13 are arranged in sequence and alternately spaced apart on the back surface 111 along a first direction and extend along a second direction. The silicon wafer 11 has a first edge 112 and a second edge 113 in the second direction, and the second direction is perpendicular to the first direction. The polarities of the first fine grid 12 and the second fine grid 13 are opposite, one of which is a positive fine grid, and the other is a negative fine grid.
[0062] Specifically, the first direction can be the stringing direction of the battery string 100 (i.e., the horizontal direction in the figure), and the second direction can be the direction perpendicular to the first direction (i.e., the vertical direction in the figure), and the two directions are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction can also be other directions, for example, two diagonal directions of the cell, which are not specifically limited here.
[0063] As Figure 2As shown, the first fine grid 12 has a plurality of first soldering points 121 for soldering the first soldering ribbons 20, and the distance between two adjacent first soldering points 121 on the same first fine grid 12 is equal. In addition, as a case, some of the first fine grids 12 in the battery piece can be provided with first soldering points.
[0064] The second fine grid 13 has a plurality of second soldering points 131 for soldering the second soldering ribbons 30, and the distance between two adjacent second soldering points 131 on the same second fine grid 13 is equal. In addition, as a case, some of the second fine grids 13 in the battery piece can be provided with second soldering points.
[0065] In the second direction, the distance between the nth first soldering point 121 on the first fine grid 12 and the nth second soldering point 131 on the second fine grid 13 is a first distance L1, and the distance between the nth second soldering point 131 on the second fine grid 13 and the (n+1)th first soldering point 121 on the first fine grid 12 is a second distance L2, the first distance L1 is different from the second distance L2, and n is a positive integer.
[0066] It can be understood that, in the battery piece, the first soldering points 121 and the second soldering points 131 are arranged alternately in the second direction, that is, as shown, Figure 2 In the adjacent first fine grid 12 and the second fine grid 13, the first soldering points 121 and the second soldering points 131 are not located on the same straight line in the first direction.
[0067] Please refer to Figure 3 and Figure 4 In the battery string 100, a plurality of back contact battery pieces 10 without main grid are arranged in the first direction (only two are shown in the figure), and the first direction is the stringing direction of the battery string 100. A plurality of first soldering ribbons 20 and a plurality of second soldering ribbons 30 are arranged alternately in the second direction and extend in the first direction, the first soldering ribbons 20 are electrically connected with the first soldering points 121 on the first fine grid 12 and are insulated from the second fine grid 13, and the second soldering ribbons 30 are electrically connected with the second soldering points 131 on the second fine grid 13 and are insulated from the first fine grid 12.
[0068] Exemplarily, the first soldering points 121 on the adjacent two first fine grids 12 are substantially aligned in the second direction, each first soldering ribbon 20 is provided with a first soldering point 121 at the intersection position of the first soldering ribbon 20 and the first fine grid 12, and the second soldering points 131 on the adjacent two second fine grids 13 are also substantially aligned in the second direction, each second soldering ribbon 30 is provided with a second soldering point 131 at the intersection position of the second soldering ribbon 30 and the second fine grid 13.
[0069] In some embodiments, the insulation of the first solder ribbons 20 and the second fine ribbons 13 can be achieved by applying insulating glue at the intersection of the two, and the insulation of the second solder ribbons 30 and the first fine ribbons 12 can also be achieved by applying insulating glue at the intersection of the two. For example, as shown in Figure 4 In some embodiments, the second fine ribbons 13 can be provided with a first insulating layer 40 at the intersection with the first solder ribbons 20, and the first fine ribbons 12 can be provided with a second insulating layer 50 at the intersection with the second solder ribbons 30. Of course, in other embodiments, the second fine ribbons 13 can also be provided with a break at the intersection with the first solder ribbons 20 to achieve the insulation of the two, and the first fine ribbons 12 can also be provided with a break at the intersection with the second solder ribbons 30 to achieve the insulation of the two, which is not limited herein.
[0070] As shown in Figure 3 In the battery string 100, the first solder ribbons 20 in the nth back contact cell without busbar 10 are electrically connected to the second solder ribbons 30 of the (n+1)th back contact cell without busbar 10, and n is a positive integer. It can be understood that the two can be separately provided and then welded together, or a continuous solder ribbon can be directly laid during the laying of the solder ribbons, which is not limited herein.
[0071] In the second direction, the distance between adjacent first solder ribbons 20 in the back contact cell without busbar 10 is equal, and the distance between adjacent second solder ribbons 30 is also equal, as shown in Figure 4 As shown in The distance between the ith first solder ribbon 20 and the ith second solder ribbon 30 in the back contact cell without busbar 10 is a third distance L4, and the distance between the ith second solder ribbon 30 and the (i+1)th first solder ribbon 20 is a fourth distance L5, the third distance L4 is different from the fourth distance L5, and i is a positive integer.
[0072] Exemplarily, please refer to Figure 5 In the battery assembly 200, the battery assembly 200 includes a first battery string 210, a second battery string 220, and a first intermediate busbar 260, the first battery string 210 is the battery string 100 described above, the second battery string 220 is obtained by rotating the first battery string 210 by 180°, and the second battery string 220 and the first battery string 210 are arranged along the first direction. The first intermediate busbar 260 is arranged between the first battery string 210 and the second battery string 220, and the first intermediate busbar 260 is electrically connected to the first solder ribbons 20 of the first battery string 210 and the first solder ribbons 20 of the second battery string 220.
[0073] In the back contact cell 10, the cell string 100, the cell module 200 and the photovoltaic system 1000 in the embodiments of the present application, the first soldering points 121 on the first fine grids 12 are directly soldered with the first solder ribbons 20, and the second soldering points 131 on the second fine grids 13 are directly soldered with the second solder ribbons 30, without the need of main grids for soldering to form the cell string 100, which can reduce the use of paste and lower the cost. Meanwhile, in the second direction, the distance between the nth first soldering point 121 on the first fine grid 12 and the nth second soldering point 131 on the second fine grid 13 is the first distance L1, and the distance between the nth second soldering point 131 on the second fine grid 13 and the (n+1)th first soldering point 121 on the first fine grid 12 is the second distance L2, and the first distance L1 is different from the second distance L2, so that the first solder ribbons 20 and the second solder ribbons 30 are distributed in a non-equidistant manner. In the case of the same size and the same number, compared with the traditional equidistant distribution scheme, the second solder ribbons 30 can be relatively close to the first solder ribbons 20, and the distance between the adjacent two first solder ribbons 20 and the distance between the adjacent two second solder ribbons 30 can also be relatively short, so as to improve the collection efficiency of carriers and further improve the efficiency of the cell.
[0074] Please refer to Figure 2 In some embodiments, in the back contact cell without main grids, the silicon wafer 11 has opposite first and second edges 112 and 113 in the second direction, and in the second direction, the end portions of the first and second fine grids 12 and 13 do not have soldering points.
[0075] In this way, the first and second edges 112 and 113 do not have the first and second solder ribbons 20 and 30 after the first and second solder ribbons 20 and 30 are arranged, and compared with the traditional uniform equidistant distribution manner, in the case of the same size and the same number, the distance between the adjacent two first solder ribbons 20 and the distance between the adjacent two second solder ribbons 30 can be relatively short, so as to shorten the transmission path of the carriers and further improve the efficiency of the cell. Meanwhile, since the first and second edges 112 and 113 do not have solder ribbons, the solder ribbons closest to the first and second edges 112 and 113 have a certain distance from the edges, and in the process of forming the module, the first or second solder ribbons 20 or 30 closest to the edges can be connected with the middle busbar without affecting the bending of the middle busbar. In this case, different types of cell strings 100 do not need to be used for manufacturing the module (i.e., the A string and B string categories in the module manufacturing process are cancelled), which can improve the manufacturing efficiency of the module.
[0076] Further, as Figure 2As shown, in some embodiments, the type of the soldering point closest to the first edge 112 is the first soldering point 121, and the distance L3 between the first soldering point 121 closest to the first edge 112 and the first edge 112 is 5mm-9mm.
[0077] In this way, by setting the distance between the first soldering point 121 closest to the first edge 112 and the first edge 112 within this reasonable range, after the first soldering ribbon 20 is subsequently soldered, the middle busbar still has sufficient length and space to be bent to connect with the junction box after the middle busbar is soldered with the first soldering ribbon 20. At the same time, it can also avoid that the distance between the soldering ribbon closest to the first edge 112 and the edge is too far, resulting in low current collection efficiency, that is, in this way, the efficiency can be taken into account, and the component cancels the A string and B string categories, and at the same time, the middle busbar can have sufficient length to be bent.
[0078] Specifically, in such embodiments, the distance between the first soldering point 121 closest to the first edge 112 and the first edge 112 can be, for example, 5mm, 5.2mm, 5.4mm, 5.4mm, 5.6mm, 5.8mm, 6mm, 6.2mm, 6.4mm, 6.6mm, 6.8mm, 7mm, 7.2mm, 7.4mm, 7.6mm, 7.8mm, 8mm, 8.2mm, 8.4mm, 8.6mm, 8.8mm, 9mm, or any value between 5mm-9mm, which is not particularly limited here.
[0079] Further, in some embodiments, the type of the soldering point closest to the second edge 113 is the first soldering point 121 or the second soldering point 131, and the distance between the first soldering point 121 or the second soldering point 131 closest to the first edge 112 and the second edge 113 is 5mm-9mm.
[0080] In this way, by setting the distance between the first soldering point 121 or the second soldering point 131 closest to the second edge 113 and the second edge 113 within this reasonable range, after the first soldering ribbon 20 or the second soldering ribbon 30 is soldered with the middle busbar, the middle busbar still has sufficient length and space to be bent to connect with the junction box. At the same time, it can also avoid that the distance between the soldering ribbon closest to the second edge 113 and the edge is too far, resulting in low current collection efficiency, that is, in this way, the efficiency can be taken into account, and the component cancels the A string and B string categories, and at the same time, the middle busbar can have sufficient length to be bent.
[0081] Specifically, in such embodiments, the distance between the first solder joint 121 or the second solder joint 131 closest to the second edge 113 and the second edge 113 can be, for example, 5 mm, 5.2 mm, 5.4 mm, 5.4 mm, 5.6 mm, 5.8 mm, 6 mm, 6.2 mm, 6.4 mm, 6.6 mm, 6.8 mm, 7 mm, 7.2 mm, 7.4 mm, 7.6 mm, 7.8 mm, 8 mm, 8.2 mm, 8.4 mm, 8.6 mm, 8.8 mm, 9 mm, or any value between 5 mm and 9 mm, without limitation.
[0082] It can be understood that, in some embodiments, the total number of all first solder joints 121 and second solder joints 131 on two adjacent first fine grids 12 and second fine grids 13 can be even or odd, such as Figure 2 As shown, when the total number of the two is even, if the solder joint closest to the first edge 112 is the first solder joint 121, the solder joint closest to the second edge 113 is the second solder joint 131 (i.e. Figure 2 As shown), if the solder joint closest to the first edge 112 is the second solder joint 131, the solder joint closest to the second edge 113 is the first solder joint 121. When the total number of the two is odd, if the solder joint closest to the first edge 112 is the first solder joint 121, the solder joint closest to the second edge 113 is also the first solder joint 121, and if the solder joint closest to the first edge 112 is the second solder joint 131, the solder joint closest to the second edge 113 is also the second solder joint 131.
[0083] Please refer to Figure 2 In some embodiments, the first distance L1 is smaller than the second distance L2. Specifically, the first distance L1 can be 4.5 mm-6.5 mm, and the second distance L2 can be 10.5 mm-12.5 mm.
[0084] In this way, by setting the first distance L1 to be smaller than the second distance L2 and reasonably designing the two, the distance between the second solder ribbon 30 closest to the first edge 112 and the first edge 112 can be not too large to affect the collection efficiency of the carriers, and at the same time, the distance between the two adjacent first solder ribbons 20 and the two adjacent second solder ribbons 30 can also be not too large to affect the collection efficiency.
[0085] Specifically, in such embodiments, the first distance L1 can be, for example, 4.5mm, 4.5mm, 5mm, 6mm, 6.5mm, or any value between 4.5mm and 6.5mm, and the second distance L2 can be, for example, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, or any value between 10.5mm and 12.5mm, without limitation here.
[0086] In some embodiments, on the first fine grid 12, the distance between two adjacent first soldering points 121 is 15.5mm-19.5mm.
[0087] In this way, the distance between two adjacent first solder strips 20 after soldering the first solder strips 20 can be avoided to be too large to affect the collection efficiency.
[0088] Specifically, in such embodiments, the distance between two adjacent first soldering points 121 can be, for example, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, or any value between 15.5mm and 19.5mm.
[0089] Similarly, in some embodiments, on the second fine grid 13, the distance between two adjacent second soldering points 131 is 15.5mm-19.5mm.
[0090] In this way, the distance between two adjacent second solder strips 30 after soldering the second solder strips 30 can be avoided to be too large to affect the collection efficiency.
[0091] Specifically, in such embodiments, the distance between two adjacent second soldering points 131 can be, for example, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, or any value between 15.5mm and 19.5mm.
[0092] Please refer to Figure 2 and Figure 4 In some embodiments, in the battery string 100, on the same piece of back contact battery piece without main grid, the type of solder strip closest to the first edge 112 is the first solder strip 20, and the distance L6 between the first solder strip 20 closest to the first edge 112 and the first edge 112 is 3mm-9mm.
[0093] Thus, by setting the spacing between the first ribbon 20 closest to the first edge 112 and the first edge 112 within this reasonable range, it can be ensured that the middle busbar still has sufficient length and space to be bent after the first ribbon 20 is welded with the middle busbar to connect with the junction box. At the same time, it can also avoid that the ribbon closest to the first edge 112 is too far away from the edge, which leads to low current collection efficiency, that is, it can ensure that the middle busbar has sufficient length to be bent while the efficiency is taken into account and the component cancels the A string and B string categories.
[0094] Specifically, in such embodiments, the spacing between the first ribbon 20 closest to the first edge 112 and the first edge 112 can be, for example, 3 mm, 3.25 mm, 3.5 mm, 3.75 mm, 4 mm, 4.25 mm, 4.5 mm, 4.75 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.25 mm, 7.5 mm, 7.75 mm, 8 mm, 8.5 mm, 9 mm, or any value between 3 mm and 9 mm, which is not specifically limited herein.
[0095] In such embodiments, the ribbon type closest to the second edge 113 is the first ribbon 20 or the second ribbon 30, and the spacing between the first ribbon 20 or the second ribbon 30 closest to the second edge 113 and the second edge 113 is 3 mm-9 mm.
[0096] Thus, by setting the spacing between the first ribbon 20 closest to the second edge 113 and the second edge 113 within this reasonable range, it can be ensured that the middle busbar still has sufficient length and space to be bent after the first ribbon 20 or the second ribbon 30 is welded with the middle busbar to connect with the junction box. At the same time, it can also avoid that the ribbon closest to the second edge 113 is too far away from the edge, which leads to low current collection efficiency, that is, it can ensure that the middle busbar has sufficient length to be bent while the efficiency is taken into account and the component cancels the A string and B string categories.
[0097] Specifically, in some embodiments, the spacing between the second ribbon 30 closest to the second edge 113 and the second edge 113 can be, for example, 3 mm, 3.25 mm, 3.5 mm, 3.75 mm, 4 mm, 4.25 mm, 4.5 mm, 4.75 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.25 mm, 7.5 mm, 7.75 mm, 8 mm, 8.5 mm, 9 mm, or any value between 3 mm and 9 mm, which is not specifically limited herein.
[0098] It is understood that, in the embodiments of this application, the sum of all first solder strips 20 and second solder strips 30 on two adjacent first fine gates 12 and second fine gates 13 can be either even or odd. When the sum of the two is even, if the solder strip closest to the first edge 112 is the first solder strip 20, then the solder strip closest to the second edge 113 is the second solder strip 30 (e.g., Figure 4 As shown, if the solder strip closest to the first edge 112 is the second solder strip 30, then the solder strip closest to the second edge 113 is the first solder strip 20. When the sum of their quantities is odd, if the solder strip closest to the first edge 112 is the first solder strip 20, then the solder strip closest to the second edge 113 is also the first solder strip 20; if the solder strip closest to the first edge 112 is the second solder strip 30, then the solder strip closest to the second edge 113 is also the second solder strip 30.
[0099] Specifically, in such an embodiment, the distance between the second solder strip 30 or the first solder strip 20 closest to the second edge 113 and the second edge 113 can be, for example, any value between 3.75mm, 4mm, 4.25mm, 4.5mm, 4.75mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.25mm, 7.5mm, 7.75mm or 3.75mm-7.75mm, and is not limited here.
[0100] Please see Figure 4 In some embodiments, the third distance L4 is smaller than the fourth distance L5. Specifically, the third distance L4 can be 2mm-4mm, and the fourth distance L5 can be 8mm-10mm.
[0101] Thus, by setting the third distance L4 to be smaller than the fourth distance L5 and designing both reasonably, the distance between the second solder strip 30 closest to the first edge 112 and the first edge 112 will not be too large and affect the carrier collection efficiency. At the same time, it can also avoid the distance between two adjacent first solder strips 20 and two adjacent second solder strips 30 being too large and affecting the collection efficiency.
[0102] Specifically, in such an embodiment, the size of the third distance L4 can be, for example, any value between 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm or 2mm-4mm, and the size of the fourth distance L5 can also be, for example, any value between 8mm, 8.5mm, 9mm, 9.5mm, 10mm or 8mm-10mm, and there is no specific limitation here.
[0103] In some embodiments, the spacing between two adjacent first solder strips 20 is 13mm-17mm.
[0104] In this way, the distance between the two adjacent first solder strips 20 after welding the first solder strips 20 can be avoided to be too large to affect the collection efficiency.
[0105] Specifically, in such embodiments, the distance between the two adjacent first solder strips 20 can be, for example, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, or any value between 13 mm and 17 mm.
[0106] Similarly, in some embodiments, the distance between the two adjacent second solder strips 30 is 13 mm-17 mm.
[0107] In this way, the distance between the two adjacent second solder strips 30 after welding the second solder strips 30 can be avoided to be too large to affect the collection efficiency.
[0108] Specifically, in such embodiments, the distance between the two adjacent second solder strips 30 can be, for example, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, or any value between 13 mm and 17 mm.
[0109] Please refer to Figure 5 In some embodiments, in the battery assembly 200, along the second direction, the solder strip closest to the first edge 112 in the battery tab closest to the first intermediate bus bar 260 in the first battery string 210 is electrically connected to the first intermediate bus bar 260. Along the second direction, the solder strip closest to the first edge 112 in the battery tab closest to the first intermediate bus bar 260 in the second battery string 220 is electrically connected to the first intermediate bus bar 260.
[0110] In this way, by arranging the first solder strips 20 and the second solder strips 30 non-equidistantly, the first battery string 210 and the second battery string 220 can be connected to the first intermediate bus bar 260 through the solder strip closest to the first edge 112 without affecting the bending of the first intermediate bus bar 260.
[0111] Please continue to refer to Figure 5 In some embodiments, the battery assembly 200 can further include a third battery string 230, a fourth battery string 240, and a second intermediate bus bar 270, the third battery string 230 being obtained by rotating the first battery string 210 by 180°, and the fourth battery string 240 being the same as the first battery string 210.
[0112] The third battery string 230 and the first battery string 210 are arranged at intervals along the second direction.
[0113] The fourth battery string 240 and the second battery string 220 are arranged at intervals along the second direction.
[0114] The third battery string 230 and the fourth battery string 240 are arranged at intervals along the first direction;
[0115] The second intermediate busbar 270 is positioned between the third battery string 230 and the fourth battery string 240. The second intermediate busbar 270 is electrically connected to the second solder strip 30 on the battery cell closest to the second intermediate busbar 270 in the third battery string 230, and also electrically connected to the second solder strip 30 on the battery cell closest to the second intermediate busbar 270 in the fourth battery string 240. The junction box (not shown) of the battery assembly 200 can be located between the first battery string 210 and the third battery string 230, where the busbar is located. The first busbar 260 and the second busbar 270 can be connected to the positive and negative terminals of the junction box, respectively.
[0116] Thus, a battery string unit can be formed by setting the third battery string 230 and the fourth battery string 240 together with the first battery string 210 and the second battery string 220.
[0117] It is understandable that, such as Figure 5 As shown, the ends of the first battery string 210 and the third battery string 230 opposite to the first intermediate busbar 260 are connected by an edge busbar 280. The edge busbar 280 connects two solder strips of different polarities in the first battery string 210 and the third battery string 230. The ends of the second battery string 220 and the fourth battery string 240 opposite to the first intermediate busbar 260 are also connected by an edge busbar 280, which connects two solder strips of different polarities in the second battery string 220 and the fourth battery string 240. It can also be understood that the assembly may include several battery string units composed of the first battery string 210, the second battery string 220, the third battery string 230, the fourth battery string 240, the first intermediate busbar 260, the second intermediate busbar 270, and several edge busbars 280. The various battery string units can be connected together through a junction box to form the assembly.
[0118] In some embodiments, along the second direction, the solder strip of the cell closest to the second edge 113 in the third battery string 230 is electrically connected to the second intermediate busbar 270.
[0119] Along the second direction, the solder strip of the cell closest to the second edge 113 in the fourth battery string 240 is electrically connected to the second intermediate busbar 270.
[0120] In this way, by arranging the first solder strips 20 and the second solder strips 30 non-equidistantly, the third cell string 230 and the fourth cell string 240 can be connected to the second intermediate busbar 270 by the solder strips closest to the second edge 113 without affecting the bending of the second intermediate busbar 270.
[0121] In the description of the present specification, the description referring to the terms "some embodiments", "illustrative embodiments", "example", "specific example", 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 refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples.
[0122] In addition, the above only the preferred embodiments of the present application, and not to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principles of the present application, etc., should be included within the scope of protection of the present application.
Claims
1. A back contact cell without a main grid, characterized in that, The battery string comprises: a plurality of back contact battery pieces without main grid as claimed in any one of claims 1-8, the plurality of back contact battery pieces without main grid are arranged in sequence and alternately in the first direction; a plurality of first solder strips and a plurality of second solder strips arranged on the back contact battery pieces without main grid, the plurality of first solder strips and the plurality of second solder strips are arranged in sequence and alternately in the second direction and extend in the first direction, the first solder strips are electrically connected with the first soldering points on the first grid and are insulated from the second grid, the second solder strips are electrically connected with the second soldering points on the second grid and are insulated from the first grid; the first solder strip in the nth back contact battery piece without main grid is electrically connected with the second solder strip of the (n+1)th back contact battery piece without main grid, and the second solder strip in the nth back contact battery piece without main grid is electrically connected with the first solder strip of the (n+1)th back contact battery piece without main grid, n is a positive integer; 2. The back contact cell as claimed in claim 1, wherein, 3. The no-finger back-contact cell according to claim 2, characterized in that, 4. The no-finger back-contact cell of claim 2, wherein, 5. The no-finger back-contact cell of claim 1, wherein, 6. The no-finger back-contact cell of claim 5, wherein, 7. The no-finger back-contact cell of claim 1, wherein, 8. The no-finger back-contact cell of claim 1, wherein, 9. A battery string, characterized by In the second direction, the distance between adjacent first solder strips in the back contact cell without main grid is equal, the distance between adjacent second solder strips is also equal, the distance between the ith first solder strip and the ith second solder strip in the back contact cell without main grid is a third distance, the distance between the ith second solder strip and the ith+1 first solder strip is a fourth distance, the third distance is different from the fourth distance, i is a positive integer.
10. The battery string of claim 9, wherein, The silicon wafer has opposite first and second edges in the second direction, and in the back contact cell without main grid, the type of solder strip closest to the first edge is the first solder strip, and the distance between the first solder strip closest to the first edge and the first edge is 3-9 mm.
11. The battery string of claim 10, wherein, The type of solder strip closest to the second edge is the first solder strip or the second solder strip, and the distance between the first solder strip or the second solder strip closest to the second edge and the second edge is 3-9 mm.
12. The battery string of claim 9, wherein, The third distance is less than the fourth distance.
13. The battery string of claim 12, wherein, The third distance is 2-4 mm in size. The fourth distance is 8-10 mm in size.
14. The battery string of claim 9, wherein, The distance between adjacent first solder strips is 13-17 mm.
15. The battery string of claim 9, wherein, The distance between adjacent second solder strips is 13-17 mm.
16. A battery assembly characterized by, Comprising: The first cell string is the cell string of any one of claims 9-14; The second cell string is obtained by rotating the first cell string by 180°, and the second cell string and the first cell string are arranged at intervals along the first direction; And The first intermediate busbar is arranged between the first cell string and the second cell string, and the first intermediate busbar is electrically connected with the first solder strip on the cell closest to the first intermediate busbar in the first cell string, and the first intermediate busbar is also electrically connected with the first solder strip on the cell closest to the first intermediate busbar in the second cell string.
17. The battery assembly of claim 16, wherein, The silicon wafer has opposite first and second edges in the second direction, and in the second direction, the solder strip closest to the first edge in the cell closest to the first intermediate busbar in the first cell string is electrically connected with the first intermediate busbar; In the second direction, the solder strip closest to the first edge in the cell closest to the first intermediate busbar in the second cell string is electrically connected with the first intermediate busbar.
18. The battery assembly of claim 16, wherein, The battery assembly further comprises a third cell string, a fourth cell string and a second intermediate busbar, the third cell string is obtained by rotating the first cell string by 180°, and the fourth cell string is the same as the first cell string; The third cell string and the first cell string are arranged at intervals along the second direction; The fourth cell string and the second cell string are arranged at intervals along the second direction; The third cell string and the fourth cell string are arranged at intervals along the first direction; The second intermediate busbar is disposed between the third battery string and the fourth battery string, the second intermediate busbar is electrically connected with a second tab on a cell tab in the third battery string closest to the second intermediate busbar, and the second intermediate busbar is also electrically connected with a second tab on a cell tab in the fourth battery string closest to the second intermediate busbar.
19. The battery assembly of claim 18, wherein, The silicon wafer has opposite first and second edges in the second direction, along the second direction, a tab in a cell tab in the third battery string closest to the second edge is electrically connected with the second intermediate busbar; Along the second direction, a tab in a cell tab in the fourth battery string closest to the second edge is electrically connected with the second intermediate busbar.
20. A photovoltaic system characterized by, The battery assembly comprises any one of claims 16-19.