Photovoltaic module
By setting up a reasonably distributed group of connection points in the photovoltaic module and adopting low-temperature welding technology, the problem of easy detachment or deviation of the welding ribbon is solved, the connection reliability is improved and the production cost is reduced.
Patent Information
- Application Number
- CN202511015551.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-23
- Publication Date
- 2025-10-03
AI Technical Summary
The soldering ribbons in photovoltaic modules are prone to falling off from the cells or deviating from the preset position, resulting in unreliable connections.
A connection point group is set on the battery cell, and the connection point group includes multiple connection points arranged at intervals along a first direction. The number of connection points in the first area is more than that in the second area. The connection points are reasonably distributed to enhance the fixing effect of the welding strip, and the connection between the welding strip and the battery cell is achieved through low-temperature welding technology.
The connection reliability between the soldering ribbon and the battery cell is improved, the probability of the soldering ribbon falling off or deviating is reduced, and the warping and hidden cracks of the battery cell caused by high-temperature welding are avoided, thereby controlling production costs.
Smart Images
Figure CN120751780A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Art
[0002] PV panels consist of cells and solder ribbons, which connect the cells together in strings. Stringing machines solder the ribbons to the cells. Due to the high temperatures involved, the cells are prone to warping, cracking, and even fragmentation. To reduce the extent of cell warping and the likelihood of cracking and fragmentation, an improved method involves pre-fixing the ribbons to the cells and then connecting them to the cells at a relatively low temperature during lamination.
[0003] Glue points are placed on the cell to adhere to the solder ribbon, pre-fixing it. However, the glue points have limited effectiveness in securing the ribbon. The center of the ribbon corresponds to the gap between the two cell cells it connects. Therefore, near the center of the ribbon, the ribbon experiences greater pullout force, making it prone to detaching from the cell or deviating from its pre-set position, resulting in the ribbon being unable to conduct current away from the cell. Summary of the Invention
[0004] The present application provides a photovoltaic module for solving the technical problem that welding ribbons are easily detached from solar cells or deviate from preset positions.
[0005] A photovoltaic module provided by an embodiment of the present application includes a cell, a connection point group and a welding ribbon, wherein the welding ribbon connects adjacent cell cells, and the connection point group is arranged between the cell cell and the welding ribbon; the connection point group includes a plurality of connection points spaced apart along a first direction, and a plurality of columns of the connection point groups are spaced apart along a second direction on the cell cell; along the first direction, the cell cell has a first area close to the center of the welding ribbon and a second area close to the end of the welding ribbon; the connection point group includes a first connection point located in the first area and a second connection point located in the second area, and the number of the first connection points is greater than the number of the second connection points; on the front side of the cell cell, the number of the first connection points is greater than the number of the first connection points on the back side of the cell cell.
[0006] In a possible design, in each column of the connection point group, the number N1 of the first connection points satisfies: 3≤N1≤7.
[0007] In a possible design, the first connection points are evenly distributed in the first area.
[0008] In a possible design, the distance d1 between adjacent first connection points satisfies: 1 mm ≤ d1 ≤ 3 mm.
[0009] In a possible design, in each column of the connection point group, the number N2 of the second connection points satisfies: 1≤N2≤3.
[0010] In one possible design, the connection point located between the first area and the second area is an intermediate connection point, and the intermediate connection points in the connection point group in odd columns and the intermediate connection points in the connection point group in even columns are alternately distributed in the second direction.
[0011] In a possible design, each column of the connection point groups has one intermediate connection point.
[0012] In a possible design, along the first direction, a distance d2 between the middle connection points in adjacent columns of the connection point groups satisfies: 5 mm ≤ d2 ≤ 12 mm.
[0013] In one possible design, along the second direction, projections of the middle connection points in the connection point groups in odd columns overlap, and / or, along the second direction, projections of the middle connection points in the connection point groups in even columns overlap.
[0014] In a possible design, along the first direction, a minimum distance d3 between the intermediate connection point and the first connection point satisfies: 5 mm ≤ d3 ≤ 12 mm.
[0015] In a possible design, along the first direction, a minimum distance d4 between the middle connection point and the second connection point satisfies: 5 mm ≤ d4 ≤ 12 mm.
[0016] In one possible design, harpoon structures are provided at both ends of the battery cell along the first direction; along the first direction, the minimum distance between the first connection point and the harpoon structure is equal to the minimum distance between the second connection point and the harpoon structure.
[0017] In a possible design, a first grid line extending along a first direction is provided on the battery cell, the connection point group is provided on the first grid line, and the number of the first grid lines is equal to the number of columns of the connection point group.
[0018] In a possible design, first gate lines extending along a first direction are provided on the battery cell, the number of the first gate lines is less than the number of columns of the connection point groups, and the connection point groups are provided on the first gate lines.
[0019] In a possible design, at least one column of the connection point groups is arranged between adjacent first gate lines.
[0020] In a possible design, when the number of the connection point groups is even, two columns of the connection point groups are arranged between the two middle first gate lines, and one column of the connection point groups is arranged between the other two adjacent first gate lines.
[0021] In a possible design, a second gate line extending along a second direction is provided on the battery cell, a pad is provided on the second gate line, the second gate line is disconnected at the pad, and the connection point group contacts at least part of the pad.
[0022] In this application, by having a greater number of first connection points than second connection points, the connection point group secures the solder ribbon in the first region more effectively than in the second region. This prevents the solder ribbon from falling off the cell or deviating from its pre-set position, and provides a highly reliable connection between the solder ribbon and the cell. Furthermore, by rationally designing the distribution of the connection points, the number of connection points per cell is not increased, thereby minimizing the production cost of the photovoltaic module.
[0023] The number of first connection points on the front side of the cell is greater than the number of first connection points on the back side of the cell. Since the soldering ribbon extends from the front side of one cell to the back side of another cell, or vice versa, the portion of the soldering ribbon near the center is subject to greater pull-out force on the front side of the cell than on the back side. Therefore, having more first connection points on the front side of the cell than on the back side of the cell can ensure that the connection points secure the soldering ribbon while reducing the overall number of connection points on the cell.
[0024] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 A schematic structural diagram of a photovoltaic module provided in this application in one embodiment;
[0026] Figure 2 for Figure 1 Schematic diagram of the partial structure of the battery cell and welding ribbon;
[0027] Figure 3 for Figure 2 A schematic structural diagram of a battery cell in one embodiment;
[0028] Figure 4 for Figure 2 A schematic structural diagram of a battery cell in another embodiment;
[0029] Figure 5 for Figure 3 、 Figure 4 A schematic structural diagram of two adjacent columns of connection point groups in FIG;
[0030] Figure 6 for Figure 2 A schematic structural diagram of a battery cell in yet another embodiment, wherein the number of columns of the connection point groups is an odd number;
[0031] Figure 7 for Figure 2 A schematic structural diagram of a battery cell in another embodiment, wherein the number of columns of the connection point groups is an even number;
[0032] Figure 8 for Figure 7 A partial enlarged view of area I.
[0033] Reference numerals:
[0034] 1-battery cell;
[0035] 1a-first area;
[0036] 1b-Second area;
[0037] 11-first grid line;
[0038] 12- second grid line;
[0039] 13- Harpoon structure;
[0040] 14- soldering pad;
[0041] 2-connection point group;
[0042] 21- first connection point;
[0043] 22- second connection point;
[0044] 23-middle connection point;
[0045] 3- welding strip;
[0046] 4-front packaging structure;
[0047] 5-front film layer;
[0048] 6-back film layer;
[0049] 7-Back side packaging structure.
[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION
[0051] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0052] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0053] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.
[0054] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.
[0055] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.
[0056] An embodiment of the present application provides a photovoltaic module, comprising a cell 1, a connection point group 2, and a welding ribbon 3. The welding ribbon 3 connects adjacent cell 1 to form a cell string. The connection point group 2 is disposed between the cell 1 and the welding ribbon 3 to pre-fix the welding ribbon 3 to the cell 1 before the welding ribbon 3 is welded to the cell 1. That is, a column of connection point groups 2 on the cell 1 corresponds to a welding ribbon 3 on the cell 1. The cell 1 has a front and a back facing each other along its thickness direction Z. The front is the light-receiving side of the cell 1, and the back is the backlight-proof side of the cell 1.
[0057] Figure 1 This is a schematic diagram of the structure of a photovoltaic module provided in this application in one embodiment. Figure 1As shown, the photovoltaic module also includes: a front encapsulation structure 4, a front film layer 5, a back film layer 6, and a back encapsulation structure 7. The front encapsulation structure 4, the front film layer 5, the back film layer 6, and the back encapsulation structure 7 encapsulate the cell string to ensure that the photovoltaic module has high mechanical strength, reduce the impact of hail impact, wind, mechanical vibration, etc. on the photovoltaic module, and improve the sealing of the photovoltaic module, enhancing its corrosion resistance and safety.
[0058] Specifically, the front encapsulation structure 4 and the back encapsulation structure 7 can be made of a rigid material such as tempered glass, polyethylene terephthalate (PET), or polycarbonate (PC), or a flexible material such as polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), or polyvinylidene fluoride (PVDF). These materials have high light transmittance, can improve the photoelectric conversion efficiency of the photovoltaic module, and ensure the power of the photovoltaic module. The front film layer 5 and the back film layer 6 can be one of the materials such as ethylene-vinyl acetate copolymer (Ethylene-Vinyl Acetate Copolymer, EVA), polyolefin elastomer (Polyolefin Elastomer, POE), polyvinyl butyral (Polyvinyl Butyral, PVB), EVA-POE-EVA co-extruded film (EPE), and EVA-POE co-extruded film (EP).
[0059] During the production process of photovoltaic modules, a cell 1 is first prepared, a connection point group 2 is coated on the cell 1 through a glue-applying device, a welding ribbon 3 is placed on the cell 1, and the connection point group 2 pre-fixes the welding ribbon 3 so that the welding ribbon 3 does not move arbitrarily relative to the cell 1. Then, multiple cell 1 are connected into a cell string through the welding ribbon 3, a front film layer 5 and a front packaging structure 4 are set on the front of the cell string, and a back film layer 6 and a back packaging structure 7 are placed on the back of the cell string. Finally, the front packaging structure 4, the front film layer 5, the cell string, the back film layer 6 and the back packaging structure 7 are laminated to form a laminate.
[0060] During the lamination process, the solder ribbon 3 alloys with the electrodes on the cell 1, achieving low-temperature welding of the solder ribbon 3 and the cell 1. Because the lamination temperature is lower than the temperature of directly welding the solder ribbon 3 to the electrodes on the cell 1, high-temperature-induced warping of the cell 1 is avoided, reducing the probability of hidden cracks and fragmentation in the cell 1, thereby improving the reliability of the produced photovoltaic modules.
[0061] It is understandable that compared to directly soldering the solder ribbon 3 to the battery cell 1, the method of achieving low-temperature welding during lamination requires the use of a low-temperature solder ribbon with a lower melting point.
[0062] Figure 2 for Figure 1 Schematic diagram of the partial structure of the battery cell 1 and the welding ribbon 3. Figure 1 and Figure 2 As shown, the electrodes on the cell 1 include a positive grid line and a negative grid line. For a cell 1 in which the positive grid line and the negative grid line are located on the front and back sides respectively, such as a Passivated Emitter Rear Cell (PERC), a Tunnel Oxide Passivated Contact (TOPCON), a Heterojunction with Intrinsic Thin-layer (HIT), a Perovskite Solar Cell (PSC), etc., the welding ribbon 3 extends from the front side of one cell 1 to the back side of another cell 1 or from the back side of one cell 1 to the front side of another cell 1 to achieve connection between adjacent cells 1.
[0063] For PERC cells, along the thickness direction, the PERC cell includes the front surface metal silver electrode, the front surface silicon nitride passivation layer, the phosphorus layer emitter, the P-type base silicon layer, the local aluminum back field, the metal aluminum back electrode, the back passivation layer (Al2O3 / SiN x PERC cells use a passivation film to passivate the back surface, replacing the all-aluminum back surface field. This enhances the internal back reflection of light in the silicon substrate, reduces the recombination rate on the back surface, and increases the photoelectric conversion efficiency of the cell by 0.5%-1%.
[0064] For a TOPCon cell, along its thickness, it consists of a metallic silver electrode, a front-surface silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, an ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metallic silver electrode. The back of the cell is composed of an ultra-thin silicon oxide layer (1nm to 2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivated contact structure. This structure can block minority carrier-hole recombination, improving the cell's open-circuit voltage and short-circuit current. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking minority carrier-hole recombination. The excellent passivation effect of the ultra-thin silicon oxide and heavily doped silicon film causes the energy bands on the silicon wafer to bend, thereby forming a field passivation effect. This significantly increases the probability of electron tunneling, reduces contact resistance, and improves the cell's open-circuit voltage and short-circuit current, thereby improving the cell's photoelectric conversion efficiency.
[0065] For HIT batteries, along their thickness direction, the HIT batteries include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.
[0066] For a PSC cell, along its thickness, the perovskite cell consists of a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with minimal loss. This can generate a high photogenerated voltage and current, making perovskites exhibit high photoelectric conversion efficiency.
[0067] Figure 3 for Figure 2 A schematic structural diagram of the battery cell 1 in one embodiment. Figure 4 for Figure 2 Schematic diagram of the structure of the battery cell 1 in another embodiment. The first direction X and the second direction Y are both perpendicular to the thickness direction Z of the battery cell 1. For example, one of the first direction X and the second direction Y is the length direction of the battery cell 1, and the other is the width direction of the battery cell 1. The first direction X and the second direction Y are perpendicular to each other.
[0068] like Figure 3 As shown, the cell 1 has a first grid line 11 extending along a first direction X and a second grid line 12 extending along a second direction Y. Exemplarily, the first grid line 11 is a main grid, and the second grid line 12 is a fine grid, i.e., a main grid cell. Multiple first grid lines 11 are spaced apart along the second direction Y, and multiple second grid lines 12 are spaced apart along the first direction X. Each first grid line 11 is connected to multiple second grid lines 12. The photocurrent generated by the cell 1 can be collected by the second grid lines 12, and the photocurrent collected by the second grid lines 12 can be collected by the first grid lines 11. A soldering pad 14 is provided on the first grid line 11, and a soldering ribbon 3 is soldered to the soldering pad 14 to connect the soldering ribbon 3 to the first grid line 11. The photocurrent in the first grid line 11 can flow to the soldering ribbon 3 through the soldering pad 14, thereby conducting current out of the cell 1. The connection point groups 2 are arranged on the first grid lines 11 . The number of the first grid lines 11 is equal to the number of columns of the connection point groups 2 , so that a welding ribbon 3 can be reliably pre-fixed on each first grid line 11 .
[0069] Specifically, first grid lines 11 include a positive main grid and a negative main grid, and second grid lines 12 include a positive fine grid and a negative fine grid. The positive main grid and the positive fine grid constitute positive grid lines, while the negative main grid and the negative fine grid constitute negative grid lines. Multiple solder pads 14 are arranged on first grid lines 11 at intervals along a first direction X. The solder pads 14 may contact the second grid lines 12 or be disposed between two second grid lines 12.
[0070] like Figure 4 As shown, the cell 1 only has a second grid line 12 extending along the second direction Y, that is, the first grid line 11 is not provided on the cell 1, that is, there is no main grid cell. The setting position of the connection point group 2 on the cell 1 corresponds to that of the main grid cell. The soldering pad 14 is provided on the second grid line 12, so that the soldering ribbon 3 can be directly connected to the second grid line 12, and the photocurrent collected by the second grid line 12 can flow directly to the soldering ribbon 3 through the soldering pad 14, thereby extracting the current from the cell 1. The main grid-free cell can reduce the amount of slurry used for the printed electrode, reduce the production cost of the cell 1, and at the same time reduce the shielding of the grid line on the surface of the cell 1, which is beneficial to improving the photoelectric conversion efficiency of the cell 1.
[0071] like Figure 3 and Figure 4 As shown, the connection point group 2 includes multiple connection points spaced apart along a first direction X, and multiple columns of connection point groups 2 are spaced apart along a second direction Y on the cell 1. Along the first direction X, the cell 1 has a first region 1a near the center of the solder ribbon 3 and a second region 1b near the end of the solder ribbon 3. The connection point group 2 includes first connection points 21 located in the first region 1a and second connection points 22 located in the second region 1b. The number of first connection points 21 is greater than the number of second connection points 22. The connection points are adhesive dots and can be shaped like squares, rectangles, circles, ellipses, triangles, etc.
[0072] Because the center of the solder ribbon 3 corresponds to the gap between the two connected cells 1, the solder ribbon 3 experiences greater pullout force near the center of the solder ribbon 3, while the pullout force is less near the ends of the solder ribbon 3. By having a greater number of first connection points 21 than second connection points 22, the connection point group 2 secures the solder ribbon 3 more effectively in the first region 1a than in the second region 1b. This prevents the solder ribbon 3 from falling off the cell 1 or deviating from its preset position, and provides a highly reliable connection between the solder ribbon 3 and the cell 1.
[0073] At the same time, by rationally designing the distribution of the connection points, the number of connection points on each cell 1 will not be increased, and thus the production cost of the photovoltaic module will not be increased.
[0074] Furthermore, the number of first connection points 21 on the front side of the cell 1 is greater than the number of first connection points 21 on the back side of the cell 1. Since the soldering ribbon 3 extends from the front side of one cell 1 to the back side of another cell 1 or vice versa, the portion of the soldering ribbon 3 near the center on the front side of the cell 1 is subject to a greater pull-out force than the portion on the back side of the cell 1. Therefore, by having a greater number of first connection points 21 on the front side of the cell 1 than on the back side of the cell 1, the overall number of connection points on the cell 1 can be reduced while ensuring that the connection points secure the soldering ribbon 3.
[0075] Specifically, in each column of connection point group 2, the number N1 of first connection points 21 satisfies: 3≤N1≤7. For example, in each column of connection point group 2, the number N1 of first connection points 21 can be: 3, 4, 5, 6, or 7.
[0076] In each column of connection point groups 2, the number N1 of first connection points 21 should be neither too many nor too few. If the number N1 of first connection points 21 is too many (for example, more than 7), the slurry required for printing the first connection points 21 increases, and the cost required for producing photovoltaic modules increases; if the number N1 of first connection points 21 is too few (for example, less than 3), the fixing effect of the first connection points 21 near the center of the welding ribbon 3 is weakened, the probability of the welding ribbon 3 falling off the battery cell 1 or deviating from the preset position increases, and the connection reliability between the welding ribbon 3 and the battery cell 1 is low.
[0077] Therefore, in each column of connection point group 2, the number N1 of first connection points 21 should be selected within an appropriate range.
[0078] Optionally, in the first region 1a, the first connection points 21 are evenly distributed, thereby facilitating the coating of the first connection points 21. Optionally, in the first region 1a, the distance between adjacent first connection points 21 gradually increases in a direction away from the center of the soldering ribbon 3, so that the fixing effect of the first connection points 21 on the soldering ribbon 3 changes with the magnitude of the pulling force applied to the soldering ribbon 3.
[0079] Specifically, in each column of connection point group 2, the number N2 of second connection points 22 satisfies: 1≤N2≤3. For example, in each column of connection point group 2, the number N2 of second connection points 22 can be: 1, 2, or 3.
[0080] In each column of connection point groups 2, the number N2 of second connection points 22 should be neither too many nor too few. If the number N2 of second connection points 22 is too many (for example, more than 3), the slurry required for printing the second connection points 22 increases, and the cost required for producing photovoltaic modules increases; if the number N2 of second connection points 22 is too few (for example, less than 1), there is no second connection point 22 in the second area 1b, and there is no fixing effect on the end of the welding ribbon 3. The end of the welding ribbon 3 can easily deviate from the preset position, thereby causing the welding ribbon 3 to be unable to export the current collected by the second grid line 12 to the battery cell 1.
[0081] Therefore, in each column of connection point group 2, the number N2 of the second connection points 22 should be selected within an appropriate range.
[0082] Figure 5 for Figure 3 、 Figure 4 A schematic diagram of the structure of two adjacent columns of connection point groups 2. Figure 5 As shown, the distance d1 between adjacent first connection points 21 satisfies the following: 1 mm ≤ d1 ≤ 3 mm. For example, the distance d1 between adjacent first connection points 21 can be: 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, etc.
[0083] The distance d1 between adjacent first connection points 21 should not be too large or too small. If the distance d1 between adjacent first connection points 21 is too large (for example, greater than 3 mm), the range of the first area 1a is too large, the first connection points 21 are relatively dispersed, and the fixing effect near the center of the welding ribbon 3 is weakened. The probability of the welding ribbon 3 falling off the battery cell 1 or deviating from the preset position increases, and the connection reliability between the welding ribbon 3 and the battery cell 1 is low; if the distance d1 between adjacent first connection points 21 is too small (for example, less than 1 mm), the precision required for coating the first connection points 21 is high, the cost required for coating the first connection points 21 increases, and the range of the first area 1a is too small, the first connection points 21 are relatively concentrated, which will also affect the fixing effect of the first connection points 21 near the center of the welding ribbon 3.
[0084] Therefore, the distance d1 between adjacent first connection points 21 should be selected within an appropriate range.
[0085] Further, such as Figures 3 to 5 As shown, the connection point between the first area 1a and the second area 1b is the intermediate connection point 23. The intermediate connection point 23 can pre-fix the welding strip 3 between the first area 1a and the second area 1b to prevent the welding strip 3 from bending and deviating from the preset position.
[0086] The intermediate connection points 23 in the odd-numbered column connection point group 2 and the intermediate connection points 23 in the even-numbered column connection point group 2 are staggered in the second direction Y, thereby improving the uniformity of the distribution of the intermediate connection points 23 on the battery cell 1. During lamination, the evenly distributed intermediate connection points 23 can evenly release thermal stress on the battery cell 1, thereby reducing hidden cracks or deformation of the battery cell 1 caused by temperature gradients.
[0087] It can be understood that the projections of the middle connection points 23 in the odd-numbered column connection point group 2 and the middle connection points 23 in the even-numbered column connection point group 2 in the second direction Y can also overlap, thereby facilitating the coating of the middle connection points 23 .
[0088] Preferably, each column of connection point groups 2 has an intermediate connection point 23, which not only serves to pre-fix the solder strip 3 but also requires less slurry to print the intermediate connection point 23, thereby ensuring that setting the intermediate connection point 23 does not significantly increase the cost required to produce photovoltaic modules.
[0089] It can be understood that according to the distance between the first area 1a and the second area 1b, the number of intermediate connection points 23 in each column of connection point group 2 can be appropriately increased, for example: the number of intermediate connection points 23 in each column of connection point group 2 can be two, three, etc.
[0090] Preferably, along the second direction Y, the projections of the intermediate connection points 23 in the odd-numbered column connection point group 2 overlap, and / or, along the second direction Y, the projections of the intermediate connection points 23 in the even-numbered column connection point group 2 overlap, so as to facilitate coating the intermediate connection points 23 together.
[0091] like Figure 5 As shown, along the first direction X, the distance d2 between the middle connection points 23 in adjacent columns of the connection point group 2 satisfies the following: 5 mm ≤ d2 ≤ 12 mm. For example, the distance d2 between the middle connection points 23 in adjacent columns of the connection point group 2 can be: 5 mm, 5.2 mm, 5.5 mm, 5.8 mm, 6 mm, 6.2 mm, 6.5 mm, 6.8 mm, 7 mm, 7.2 mm, 7.5 mm, 7.8 mm, 8 mm, 8.2 mm, 8.5 mm, 8.8 mm, 9 mm, 9.2 mm, 9.5 mm, 9.8 mm, 10 mm, 10.2 mm, 10.5 mm, 10.8 mm, 11 mm, 11.2 mm, 11.5 mm, 11.8 mm, 12 mm, etc.
[0092] Along the first direction X, the distance d2 between the intermediate connection points 23 in adjacent column connection point groups 2 should not be too large or too small. If the distance d2 between the intermediate connection points 23 in adjacent column connection point groups 2 is too large (for example, greater than 12 mm), the intermediate connection points 23 will be farther away from the first area 1a or the second area 1b, so that the pre-fixation of the intermediate connection points 23 to the welding ribbon 3 is weaker, and the welding ribbon 3 cannot be effectively prevented from bending and deviating from the preset position; if the distance d2 between the intermediate connection points 23 in adjacent column connection point groups 2 is too small (for example, less than 5 mm), the uniformity of the distribution of the intermediate connection points 23 on the battery cell 1 will be reduced, thereby failing to evenly release the thermal stress on the battery cell 1 during lamination, which can easily cause hidden cracks or deformation of the battery cell 1.
[0093] Therefore, along the first direction X, the distance d2 between the middle connection points 23 in adjacent columns of the connection point groups 2 should be selected within an appropriate range.
[0094] like Figure 5 As shown, along the first direction X, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 satisfies the following: 5mm≤d3≤12mm. For example, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 can be: 5mm, 5.2mm, 5.5mm, 5.8mm, 6mm, 6.2mm, 6.5mm, 6.8mm, 7mm, 7.2mm, 7.5mm, 7.8mm, 8mm, 8.2mm, 8.5mm, 8.8mm, 9mm, 9.2mm, 9.5mm, 9.8mm, 10mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, 12mm, etc.
[0095] Along the first direction X, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 should not be too large or too small. If the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 is too large (for example, greater than 12 mm), the welding ribbon 3 between the intermediate connection point 23 and the first connection point 21 is easy to bend and deviate from the preset position; if the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 is too small (for example, less than 5 mm), the distance between the intermediate connection point 23 and the second connection point 22 will be too large, and the welding ribbon 3 between the intermediate connection point 23 and the second connection point 22 will be easy to bend and deviate from the preset position.
[0096] Therefore, along the first direction X, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 should be selected within an appropriate range.
[0097] like Figure 5As shown, along the first direction X, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 satisfies the following: 5mm≤d4≤12mm. For example, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 can be: 5mm, 5.2mm, 5.5mm, 5.8mm, 6mm, 6.2mm, 6.5mm, 6.8mm, 7mm, 7.2mm, 7.5mm, 7.8mm, 8mm, 8.2mm, 8.5mm, 8.8mm, 9mm, 9.2mm, 9.5mm, 9.8mm, 10mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, 12mm, etc.
[0098] Along the first direction X, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 should not be too large or too small. If the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 is too large (for example, greater than 12 mm), the welding ribbon 3 between the intermediate connection point 23 and the second connection point 22 is easy to bend and deviate from the preset position; if the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 is too small (for example, less than 5 mm), the distance between the intermediate connection point 23 and the first connection point 21 will be too large, and the welding ribbon 3 between the intermediate connection point 23 and the first connection point 21 will be easy to bend and deviate from the preset position.
[0099] Therefore, along the first direction X, the minimum distance d4 between the middle connection point 23 and the second connection point 22 should be selected within an appropriate range.
[0100] like Figure 3 and Figure 4 As shown, along the first direction X, harpoon structures 13 are provided at both ends of the cell 1. Harpoon structures 13 collect the current collected by the second busbar 12 at the ends of the cell 1 to ensure the photovoltaic module's photoelectric conversion efficiency. For cells with a main grid, the harpoon structures 13 are connected to the first busbar 11; for cells without a main grid, the harpoon structures 13 are provided directly at both ends of the cell 1.
[0101] like Figure 5 As shown, along the first direction X, the minimum distance between the first connection point 21 and the harpoon structure 13 is equal to the minimum distance between the second connection point 22 and the harpoon structure 13, so that when coating the first connection point 21 and the second connection point 22, the harpoon structure 13 can be used to position them at the same distance, reducing the probability of incorrect coating position of the connection point.
[0102] Figure 6 for Figure 2 Schematic diagram of the structure of the battery cell 1 in another embodiment, wherein the number of columns of the connection point group 2 is an odd number. Figure 7 for Figure 2Schematic diagram of the structure of the battery cell 1 in another embodiment, wherein the number of columns of the connection point group 2 is an even number.
[0103] like Figure 6 and Figure 7 As shown, the number of first gridlines 11 is less than the number of columns of connection point groups 2. Some connection point groups 2 are located on the first gridlines 11, thereby combining the advantages of both busbar-equipped and busbar-free cells. By reducing the number of first gridlines 11 on a cell 1, the amount of paste required to print the first gridlines 11 can be reduced, thereby reducing the production cost of the photovoltaic module.
[0104] Specifically, at least one column of connection point groups 2 is provided between adjacent first grid lines 11. Depending on actual working conditions, one, two, three or more columns of connection point groups 2 can be provided between adjacent first grid lines 11 to balance the photoelectric conversion efficiency and production cost of the photovoltaic module.
[0105] like Figure 7 As shown, when the number of connection point groups 2 is an even number, two columns of connection point groups 2 are provided between the two middle first grid lines 11, and one column of connection point groups 2 is provided between the other two adjacent first grid lines 11, so that the connection point groups 2 located at both ends of the battery cell 1 along the second direction Y are all provided on the first grid lines 11, that is, the welding strips 3 located at both ends of the battery cell 1 along the second direction Y are all connected to the first grid lines 11, rather than directly to the second grid lines 12, thereby ensuring the extraction effect of the current generated at both ends of the battery cell 1 in the second direction Y.
[0106] Figure 8 for Figure 7 A partial enlarged view of the middle Ⅰ area. Figure 8 As shown, the second grid lines 12 are disconnected at the pads 14, and the connection point group 2 contacts at least a portion of the pads 14. By disconnecting the second grid lines 12, the paste required for printing the second grid lines 12 can be reduced, thereby reducing the production cost of the photovoltaic module. To ensure the reliability of the connection between the pads 14 and the second grid lines 12, the pads 14 can be in an I-shape, with the two ends of the I-shaped pad 14 corresponding to the second grid lines 12 on both sides. It is understood that the pads 14 can also have other shapes.
[0107] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.
Claims
1. A photovoltaic module, characterized in that: The photovoltaic module comprises a cell (1), a connection point group (2) and a welding ribbon (3), wherein the welding ribbon (3) connects adjacent cell slices (1), and the connection point group (2) is arranged between the cell slice (1) and the welding ribbon (3); The connection point group (2) includes a plurality of connection points spaced apart along a first direction (X), and a plurality of columns of the connection point group (2) are spaced apart along a second direction (Y) on the battery sheet (1); Along the first direction (X), the battery cell (1) has a first region (1a) close to the center of the welding ribbon (3) and a second region (1b) close to the end of the welding ribbon (3); The connection point group (2) includes first connection points (21) located in the first area (1a) and second connection points (22) located in the second area (1b), and the number of the first connection points (21) is greater than the number of the second connection points (22); On the front side of the battery cell (1), the number of the first connection points (21) is greater than the number of the first connection points (21) on the back side of the battery cell (1).
2. The photovoltaic module according to claim 1, characterized in that In each column of the connection point group (2), the number N1 of the first connection points (21) satisfies: 3≤N1≤7.
3. The photovoltaic module according to claim 1, characterized in that In the first area (1a), the first connection points (21) are evenly distributed.
4. The photovoltaic module according to claim 3, characterized in that The distance d1 between adjacent first connection points (21) satisfies: 1mm≤d1≤3mm.
5. The photovoltaic module according to claim 1, characterized in that In each column of the connection point group (2), the number N2 of the second connection points (22) satisfies: 1≤N2≤3.
6. The photovoltaic module according to claim 1, characterized in that The connection point located between the first area (1a) and the second area (1b) is an intermediate connection point (23), and the intermediate connection points (23) in the connection point group (2) in the odd columns and the intermediate connection points (23) in the connection point group (2) in the even columns are staggered in the second direction (Y).
7. The photovoltaic module according to claim 6, characterized in that: Each column of the connection point group (2) has one intermediate connection point (23).
8. The photovoltaic module according to claim 7, characterized in that: Along the first direction (X), the distance d2 between the intermediate connection points (23) in the connection point groups (2) in adjacent columns satisfies: 5mm≤d2≤12mm.
9. The photovoltaic module according to claim 6, characterized in that: Along the second direction (Y), the projections of the intermediate connection points (23) in the connection point groups (2) in odd columns coincide with each other, and / or, along the second direction (Y), the projections of the intermediate connection points (23) in the connection point groups (2) in even columns coincide with each other.
10. The photovoltaic module according to claim 6, characterized in that: Along the first direction (X), the minimum distance d3 between the intermediate connection point (23) and the first connection point (21) satisfies: 5mm≤d3≤12mm.
11. The photovoltaic module according to claim 6, characterized in that: Along the first direction (X), the minimum distance d4 between the middle connection point (23) and the second connection point (22) satisfies: 5mm≤d4≤12mm.
12. The photovoltaic module according to claim 1, characterized in that Along the first direction (X), harpoon structures (13) are provided at both ends of the battery sheet (1); Along the first direction (X), the minimum distance between the first connection point (21) and the harpoon structure (13) is equal to the minimum distance between the second connection point (22) and the harpoon structure (13).
13. The photovoltaic module according to any one of claims 1 to 12, characterized in that: The battery cell (1) is provided with a first grid line (11) extending along a first direction (X), the connection point group (2) is provided on the first grid line (11), and the number of the first grid lines (11) is equal to the number of columns of the connection point group (2).
14. The photovoltaic module according to any one of claims 1 to 12, characterized in that: The battery cell (1) is provided with first grid lines (11) extending along a first direction (X), the number of the first grid lines (11) is less than the number of columns of the connection point group (2), and the connection point group (2) is provided on the first grid lines (11).
15. The photovoltaic module according to claim 14, characterized in that: At least one column of the connection point groups (2) is arranged between adjacent first gate lines (11).
16. The photovoltaic module according to claim 14, characterized in that: When the number of the connection point groups (2) is an even number, two columns of the connection point groups (2) are provided between the middle two first gate lines (11), and one column of the connection point groups (2) is provided between the other two adjacent first gate lines (11).
17. The photovoltaic module according to any one of claims 1 to 12, characterized in that: The battery cell (1) is provided with a second grid line (12) extending along a second direction (Y), a welding pad (14) is provided on the second grid line, the second grid line (12) is disconnected at the welding pad (14), and the connection point group (2) is in contact with at least part of the welding pad (14).