Photovoltaic panels and photovoltaic systems

Abstract

The present invention discloses a photovoltaic module and a photovoltaic system. The photovoltaic module includes a cell and an interconnection. The cell has a busbar. An interconnection connects the busbars on adjacent cells. The busbars and the interconnection are fixed and electrically connected via a bonding layer. On the surface of a cell, an interconnection is fixed with a bonding layer over more than 60% of its length. In an embodiment of the present invention, the bonding layer is fixed to the interconnection and the busbar for a long length, which can improve the bonding force and fixing effect of the interconnection and the cell.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a photovoltaic component and a photovoltaic system. Background Art

[0002] Photovoltaic modules include cells and welding strips, which are used to interconnect the cells. The cells are usually welded to the welding strips through multiple pads on them.

[0003] However, when the battery cell and the soldering ribbon are soldered at low temperature, the bonding force formed at the soldering interface is weak, the soldering effect between the soldering ribbon and the battery cell is limited, and the pull-off force between the soldering ribbon and the battery cell is limited. Summary of the invention

[0004] The present invention provides a photovoltaic module and a photovoltaic system, aiming to at least solve the technical problems in the prior art that the welding effect between the welding ribbon and the battery cell is limited and the pulling force between the welding ribbon and the battery cell is limited.

[0005] An embodiment of the present invention provides a photovoltaic module, comprising a cell and an interconnection member, wherein the cell has a busbar, and the interconnection member connects the busbars on adjacent cell sheets;

[0006] The busbar and the interconnection member are fixed and electrically connected via a bonding layer;

[0007] On the surface of the battery sheet, the bonding layer is fixed to an interconnection member over more than 60% of its length.

[0008] In the embodiment of the present invention, a bonding layer is fixed to an interconnection member on the surface of a battery cell over a range of more than 60% of its length, that is, the fixing length of the bonding layer and the interconnection member is relatively long, which can increase the fixing area of ​​the bonding layer, the interconnection member and the confluence portion on the battery cell, thereby improving the bonding force and fixing effect of the interconnection member and the battery cell, improving the pull-off force between the interconnection member and the battery cell, and thus meeting the reliability requirements of the photovoltaic module.

[0009] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the partial structure of the cell and the bonding layer in the photovoltaic module provided by the embodiment of the present invention Figure 1 ;

[0011] Figure 2 Schematic diagram of the partial structure of the cell and the bonding layer in the photovoltaic module provided by the embodiment of the present invention Figure 2 ;

[0012] Figure 3 A schematic diagram of a portion of the structure of a cell, a bonding layer and an interconnection member in a photovoltaic module provided by an embodiment of the present invention;

[0013] Figure 4 A partial cross-sectional schematic diagram of a cell sheet, a bonding layer and an interconnection member in a photovoltaic module provided by an embodiment of the present invention;

[0014] Figure 5 A schematic diagram of a printing pattern of a bonding layer in a photovoltaic module provided in an embodiment of the present invention.

[0015] Reference numerals:

[0016] 1-battery cell, 11-bus electrode, 111-solder pad, 112-connecting wire, 113-suspension part, 12-collecting electrode, 13-insulating member, 14-battery cell body, 2-joining layer, 21-joining segment, 22-joining suspension part, 23-first joining segment, 24-second joining segment, 3-interconnection member. DETAILED DESCRIPTION

[0017] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0018] Reference Figures 1 to 3 An embodiment of the present invention discloses a photovoltaic module, which includes a battery cell 1 and an interconnection member 3. The battery cell 1 has a busbar, and an interconnection member 3 connects the busbars on adjacent battery cells 1; the busbar and the interconnection member 3 are fixed and electrically connected by a bonding layer 2; on the surface of a battery cell 1, an interconnection member 3 is fixed with a bonding layer 2 over a range of more than 60% of its length.

[0019] Among them, the battery cell 1 can be a back-contact battery cell or a battery cell with double-sided electrodes. The front side of the back-contact battery cell has no electrode, and has the characteristics of low shading loss and beautiful appearance. Multiple battery cells 1 are connected in series through an interconnection member 3. The interconnection member 3 can be a welding strip or a film-coated welding strip, wherein the welding strip is a flat welding strip or a round welding strip, and the welding strip can also be set to a welding strip of other shapes according to actual needs. The welding strip can be a tinned welding strip. When the battery cell 1 is a back-contact battery cell, the interconnection member 3 is preferably a flat welding strip. The battery cell 1 and the interconnection member 3 are welded through the bonding layer 2.

[0020] The busbar and the interconnection member 3 are fixed by the bonding layer 2, and the busbar and the interconnection member 3 are electrically connected by the bonding layer 2. The busbar and the interconnection member 3 are specifically welded by the bonding layer 2. The bonding layer 2 can be a conductive glue or a conductive paste, which can play a role of fixing and conducting electricity during the welding process of the interconnection member 3 and the battery cell 1. The height of the bonding layer 2 can be set according to actual needs, for example, it can be set to 25μm-35μm.

[0021] The total length of a single interconnection member 3 can be set according to actual needs, for example, it can be set to 172 mm. The total length of a single interconnection member 3 is L1, the length of an interconnection member 3 on the surface of a battery cell 1 is L2, and a bonding layer 2 is fixed to an interconnection member 3 along a range of more than 60% L2 of its length, wherein L2 is less than L1.

[0022] In the related art, when the electrode on the battery cell is welded to the welding strip at a low temperature, the bonding force formed at the welding interface is weak, the welding effect between the welding strip and the electrode is limited, and the pull-off force between the welding strip and the electrode is limited. In the embodiment of the present invention, on the surface of a battery cell 1, an interconnection member 3 is fixed with a bonding layer 2 over a range of more than 60% along its length direction, that is, the fixed length of the bonding layer 2 and the interconnection member 3 is relatively long, which can increase the fixing area of ​​the bonding layer 2 and the interconnection member 3 and the confluence of the battery cell 1, thereby improving the bonding force and fixing effect of the interconnection member 3 and the battery cell 1, and improving the pull-off force between the interconnection member 3 and the battery cell 1, thereby meeting the reliability requirements of the photovoltaic module. Among them, the pull-off force between the interconnection member 3 and the confluence refers to the force required to pull the interconnection member 3 off the confluence.

[0023] It should be understood that fixing the bonding layer 2 does not require that a certain position on the confluence portion is fully covered by the bonding layer 2 in the width direction. A certain position on the confluence portion can be deemed to be fixed with the bonding layer 2 if it is partially covered by the bonding layer 2.

[0024] It should be noted that the bonding layer 2 may be a single-layer structure or a multi-layer structure. When the bonding layer 2 is a multi-layer structure, its mechanical stability can be improved. The length direction of the confluence portion and the length direction of the bonding layer 2 are consistent with the length direction of the interconnection member 3, and the width direction of the confluence portion and the width direction of the bonding layer 2 are consistent with the width direction of the interconnection member 3.

[0025] In some embodiments, on the surface of a battery cell 1, an interconnection member 3 is fixed with a bonding layer 2 over 82% of its length, and in this case, it can be ensured that the interconnection member 3 on the battery cell 1, except for the process reserved areas at both ends, that is, the area between the two end pads of the interconnection member 3, fully covers the bonding layer 2. The fixed length of the bonding layer 2, the interconnection member 3 and the busbar can be further increased, thereby further improving the bonding force and fixing effect of the interconnection member 3 and the busbar.

[0026] Reference Figures 1 to 4 The battery cell 1 includes a battery cell body 14, and the battery cell 1 has a collector electrode 12. The confluence portion can be Figures 1 to 3 The bus electrode 11 shown in the figure can also be composed of a connecting portion for current convergence arranged on multiple collecting electrodes 12 and located below the interconnection member 3 (not shown in the figure); it can also be composed of a thickened portion located below the interconnection member 3 on multiple collecting electrodes 12 (not shown in the figure); it can also be a segmented electrode, for example, Figure 1 The bus electrode in the design is divided into multiple sections. Of course, the bus electrode 11 described below can omit the connecting wire 112, and retain the pad 111 set on the battery cell 1. The multiple pads 111 under the interconnection member 3 can also constitute the bus portion of the battery cell 1.

[0027] When the busbar is a busbar electrode 11, the busbar electrode 11 is formed on the cell body 14. The structure and specifications of the cell body 14 can be set according to actual conditions and are not specifically limited here. The shape of the cross section of the busbar electrode 11 perpendicular to its length direction can be square, quasi-square, trapezoidal, circular, triangular, quasi-triangular, etc. The shape of the cross section of the bonding layer 2 perpendicular to its length direction can be square, quasi-square, trapezoidal, etc.

[0028] When the busbar portion is a busbar electrode 11, the battery cell 1 has a plurality of busbar electrodes 11, and the plurality of busbar electrodes 11 are arranged at intervals along the width direction (direction B). The length direction of the busbar electrode 11 can refer to Figure 1 , Figure 3 and Figure 4 The direction indicated by the arrow A in FIG. 1 is the width direction of the bus electrode 11. Figure 1 and Figure 3 The direction indicated by the arrow B in FIG. An interconnector 3 connects the corresponding bus electrodes 11 on two adjacent battery cells 1 to realize the series connection of the battery cells 1. The bus electrode 11 includes a plurality of pads 111 and a plurality of connecting wires 112. The pads 111 and the connecting wires 112 are connected and electrically conductive. Two adjacent pads 111 are connected by a connecting wire 112. The size of the pad 111 can be set according to actual needs, for example, it can be set to 1mm×1.2mm, 1mm×0.8mm, 1mm×0.6mm, 0.8mm×0.6mm, 0.8mm×0.6mm, etc.

[0029] In some embodiments, the bus portion is a bus electrode 11 extending in the same direction as the interconnection member 3, and a bus electrode 11 is fixed with a bonding layer 2 over 70% of its length. The plurality of pads 111 include two end pads respectively close to the two ends of the bus electrode 11, and preferably, a bonding layer 2 is fixed between the two end pads in a bus electrode 11. In this embodiment, the two end pads on the bus electrode 11 and the area therebetween are effective welding areas, and the bonding layer 2 is fixed to the area, which can greatly increase the fixing area of ​​the bonding layer 2 with the interconnection member 3 and the bus electrode 11, thereby improving the bonding force and fixing effect of the interconnection member 3 and the bus electrode 11.

[0030] In some embodiments, the busbar is disposed on the collector electrode 12 .

[0031] In some embodiments, the converging portion is a multi-segment electrode, which can reduce the material loss of the converging portion and improve the current convergence effect on the collector electrode 12. For example, the converging electrode 11 can be interrupted to set multiple gaps.

[0032] In some embodiments, the busbar includes a plurality of pads 111 , and the peeling force between more than 80% of the pads 111 in a busbar and the interconnection member 3 is greater than or equal to 1N.

[0033] Preferably, the peeling force between more than 90% of the pads 111 and the interconnection part 3 is greater than or equal to 1N. It should be noted that more than 80% of the pads 111 in a bus refers to more than 80% of the pads 111 in a bus. The number of pads 111 in a bus can be set according to actual needs, for example, it can be set to 7, 8, 10, 20, 21, 22, etc. When the number of pads 111 in a bus is 7, the peeling force between more than 6 pads 111 in a bus and the interconnection part 3 is greater than or equal to 1N. The bus here can be a bus electrode 11, and the bus electrode 11 includes a connecting line 112 and a pad 111. The bus can also be composed of multiple pads 111, or the bus is a segmented electrode.

[0034] In this embodiment, when the bus portion is the bus electrode 11, the pad 111 on the bus electrode 11 is the position where the bonding force between the bus electrode 11 and the interconnection component 3 is relatively large. When more than 80% of the pads 111 can provide a peeling force of more than 1N, it can ensure that the effective welding points between the entire bus electrode 11 and the interconnection component 3 account for the majority, and the connection quality is high.

[0035] In some embodiments, between a busbar and an interconnection member 3, the bonding layer 2 is in a strip shape, in which case point, line contact or line-to-line contact can be achieved, thereby enhancing the reliability of the bonding between the battery cell and the interconnection member. When the busbar is a busbar electrode 11, the shape of the bonding layer 2 matches the shape of the interconnection member 3 and the busbar electrode 11. The interconnection member 3 and the busbar electrode 11 are both in a strip shape. Compared with the point-shaped bonding layer 2, the strip-shaped bonding layer 2 matches the shape between the two, so that the busbar electrode 11 and the interconnection member 3 achieve surface contact rather than discrete point contact, so that the fixed forces at various positions between the busbar electrode 11 and the interconnection member 3 are connected, reducing the existence of weak points in the bonding between the busbar electrode 11 and the interconnection member 3.

[0036] In some embodiments, the bonding layer 2 includes at least one independent bonding layer segment, and the length of the bonding layer segment is greater than the width. The bonding layer 2 may include discrete, independent bonding layer segments of 1, 2, 3, 7, 8, 16, 21, etc. The length direction and width direction of the bonding layer segment are consistent with the interconnection element 3. When the length of the bonding layer segment is greater than the width, the strip characteristics of the bonding layer 2 can be achieved.

[0037] In some embodiments, the battery cell 1 also has a collector electrode 12; on a battery cell, a plurality of M positions are provided on the confluence corresponding to an interconnect 3, and the M position is the intersection position of the confluence and the collector electrode 12, and at least 10 M positions on a confluence have intermetallic compounds. In this embodiment, the position where the confluence intersects with the collector electrode 12 can be named as the M position for ease of description. When the confluence is a strip-shaped confluence electrode 11 or a segmented electrode, the M position is the intersection position of the strip-shaped confluence electrode 11, the segmented electrode and the strip-shaped collector electrode 12. When the confluence is a dot-shaped thickened portion, a pad 111 or other structure, the M position is a position corresponding to the collector electrode 12, such as a thickened portion, a pad 111, or a connecting portion on the collector electrode 12 constituting the confluence.

[0038] Among them, when the busbar portion is a busbar electrode 11, in actual use, the collector electrode 12 collects the carriers generated in the corresponding area of ​​the battery cell body 14, and the busbar electrode 11 is used to collect the carriers collected by the collector electrode 12 intersecting with it. The extension direction of the collector electrode 12 is preferably perpendicular to the extension direction of the busbar electrode 11. The battery cell 1 has a plurality of collector electrodes 12, and the plurality of collector electrodes 12 include a plurality of positive collector electrodes 12 and a plurality of negative collector electrodes 12, and the plurality of positive collector electrodes 12 and the plurality of negative collector electrodes 12 are alternately arranged along the length direction of the busbar electrode 11.

[0039] The confluence below an interconnect 3 on a battery cell 1 can be understood as a confluence. A bonding layer 2 forms intermetallic compounds at at least 10 M positions with a confluence. If a confluence intersects with 50-130 collector electrodes 12 within the length range, that is, the number of M positions is 50-130. Intermetallic compounds may be formed at 10 M positions, preferably at least half of the M positions, and preferably at the intersection of each collector electrode 12 and the confluence. Intermetallic compounds generally have high mechanical strength and electrical conductivity. For the intersection of the confluence and multiple collector electrodes 12, when more than 10 intermetallic compounds are formed, there are more intermetallic compound connection points, which can improve the fixing effect of the bonding layer 2 and the confluence.

[0040] In the related art, at the non-pad 111 position of the bus electrode 11, the current needs to be transmitted along the length direction of the bus electrode 11. This long-distance transmission will increase the resistance loss, thereby reducing the transmission efficiency. In this embodiment, at at least 10 M positions with intermetallic compounds, the collector electrode 12 can achieve electrical conduction in the vertical direction through the bus electrode 11, the intermetallic compound, the bonding layer 2 and the interconnection member 3, which can shorten the current transmission distance, improve the current transmission efficiency, and thus improve the CTM (Cell To Module, the conversion efficiency of the battery cell to the component) data.

[0041] In some embodiments, the current collecting electrode 12 is a continuous current collecting electrode. In this case, compared with the interrupted current collecting electrode, the continuous current collecting electrode has a better current collecting effect.

[0042] In some embodiments, the collector electrode 12 has a plurality of M positions, where the M positions are intersections of the collector electrode 12 and the confluence portion, and 3 to 14 M positions on each collector electrode 12 have intermetallic compounds.

[0043] Among them, the bonding layer 2 and the collector electrode 12 form an intermetallic compound at the M position. Preferably, each collector electrode 12 has an intermetallic compound at 5-12 M positions. Specifically, the number of positions with intermetallic compounds on each collector electrode 12 may be the same or different. At the M position with the intermetallic compound, the collector electrode 12 can achieve electrical conduction in the vertical direction through the confluence, the intermetallic compound, the bonding layer 2 and the interconnect 3, which can shorten the current transmission distance and improve the current transmission efficiency. At this time, each collector electrode 12 can perform fast and short-distance current transmission through the intermetallic compounds at multiple M positions, which can improve the current transmission efficiency of all collector electrodes 12 and the entire battery cell 1.

[0044] In some embodiments, at least one collector electrode 12 is in direct contact with the bonding layer 2, and the collector electrode 12 is electrically connected to the interconnection member 3 through the bonding layer 2. It should be understood that when the collector electrode 12 is in direct contact with the bonding layer 2, the two may also be in indirect contact.

[0045] In the present embodiment, while the collector electrode 12 transmits current through the confluence, the bonding layer 2, and the interconnection member 3, the collector electrode 12 is also in direct contact with the bonding layer 2, further reducing the current loss at the confluence, allowing the current to be transmitted quickly and unimpeded over a short distance between the collector electrode 12 and the bonding layer 2, thereby shortening the current transmission distance and improving the current transmission efficiency.

[0046] In some embodiments, the bonding layer 2 includes a first bonding segment 23 and a second bonding segment 24, wherein the width of the first bonding segment 23 is greater than the width of the second bonding segment 24. The first bonding segment 23 fixes the bottom of the interconnection member 3 and at least part of the side surface of the interconnection member 3; the second bonding segment 24 fixes the bottom of the interconnection member 3. The first bonding segment 23 and the second bonding segment 24 may be two discrete, unconnected segments, or may be different parts of a bonding layer connected together.

[0047] The interconnection member 3 has two side surfaces arranged opposite to each other along its width direction, and the first bonding segment 23 preferably fixes the bottom of the interconnection member 3 and the two side surfaces of the interconnection member 3. When the busbar portion is a busbar electrode 11, and the busbar electrode 11 includes a plurality of pads 111, the number of the first bonding segments 23 is greater than or equal to the number of pads 111, and preferably each pad 111 has a first bonding segment 23 on it, and one or two first bonding segments 23 are provided between two adjacent pads 111. The number of the first bonding segments 23 may be greater than or equal to 7, and the number of the first bonding segments 23 is preferably 21.

[0048] In this embodiment, the first bonding segment 23 fixes the bottom of the interconnection member 3 and at least part of the side surface of the interconnection member 3, which can increase the fixing area of ​​the bonding layer 2 and the interconnection member 3 and present a wrapping effect, thereby improving the fixing effect of the bonding layer 2 and the interconnection member 3. In addition, the width of the second bonding segment 24 is smaller than the width of the first bonding segment 23, which can reduce the material consumption of the bonding layer 2 while ensuring the fixing effect of the bonding layer 2 and the interconnection member 3.

[0049] When the bonding layer 2 is printed, it can be printed according to Figure 5The printed pattern shown prints multiple junctions U. During the interconnection process between the interconnection member 3 and the battery cell 1, multiple junctions U will melt and form continuous or discontinuous strips. After the interconnection between the interconnection member 3 and the battery cell 1 is completed, the junction layer 2 is in a strip shape between a conduit and the interconnection member 3, or the junction layer 2 includes at least one independent junction layer segment, and the length of the junction layer segment is greater than the width. When the junction layer 2 is printed, it can be printed through a screen with mesh holes. The size of the printed junction can be set according to actual needs, for example, it can be set to 0.8mm×0.8mm.

[0050] In some embodiments, there is a second bonding segment 24 between two adjacent first bonding segments 23. Adjacent first bonding segments 23 and second bonding segments 24 can be connected. In this case, the first and second bonding segments are arranged alternately, which can effectively reduce material loss and ensure uniform fixing force between the confluence portion and the interconnection member 3 while ensuring effective connection between the confluence portion and the interconnection member 3.

[0051] In some embodiments, the bonding layer 2 and the busbar form an intermetallic compound; the intermetallic compound formed by the bonding layer 2 and the busbar includes a portion A and a portion B, and along the width direction of the interconnect 3, the width of the portion A is greater than the width of the portion B. The width of the portion A and the width of the portion B may be the maximum width of the corresponding intermetallic compound.

[0052] Preferably, when the bonding layer 2 includes the first bonding segment 23 and the second bonding segment 24, the intermetallic compound formed by the first bonding segment 23 and the confluence portion is part A, and the intermetallic compound formed by the second bonding segment 24 and the confluence portion is part B. The wider the width of the intermetallic compound, the better the fixing effect between the bonding layer 2 and the confluence portion. In this embodiment, by setting the parts A and B of different widths, the material consumption of the bonding layer 2 can be reduced while ensuring the fixing effect between the bonding layer 2 and the confluence portion. Compared with the case where the confluence portion is all intermetallic compound of part B, this embodiment can reduce resistance and improve current transmission efficiency.

[0053] In some embodiments, along the length direction of the interconnection member 3, there is a B part between two adjacent A parts. Preferably, along the length direction of the interconnection member 3, any adjacent A parts are connected to the B part. At this time, the A part and the B part are alternately distributed, which can release the current transmission pressure compared with the concentrated distribution of the A part and the B part or the equal width design of the metal compound. In addition, the A part with a larger fixing force and the B part with a smaller fixing force are distributed between the interconnection member 3 and the confluence part, and the fixing force is distributed in a stepped manner, which can be supplemented when the fixing force of the B part is insufficient.

[0054] In some embodiments, at least one of the A portions is closer to the end of the interconnection member 3 than the B portion. The closer to the end of the interconnection member 3, that is, the edge of the battery cell 1, the weaker the current is. In this embodiment, at least one of the A portions with a larger width is closer to the end of the interconnection member 3 than the B portion, which can improve the current collection and transmission efficiency at the end of the interconnection member 3 and improve the effective collection of the current in the edge area of ​​the battery cell.

[0055] In some embodiments, a portion A is connected to a portion B. At this time, the portions A and B are combined together rather than in a discrete state, so that the forces of the portions A and B can be well combined, thereby improving the current transmission effect and fixing effect between the interconnection member 3 and the confluence portion.

[0056] In some embodiments, the maximum width of the bonding layer 2 is less than or equal to 1.2 mm and greater than or equal to 0.06 mm; the minimum width of the bonding layer 2 is greater than or equal to 0.06 mm and less than or equal to 1.2 mm.

[0057] In this embodiment, when the maximum width of the bonding layer 2 is less than or equal to 1.2 mm, the risk of short circuit caused by the bonding layer 2 overflowing to the opposite collector electrode 12 can be avoided. If the width of the bonding layer 2 is too small, the bonding layer 2 may be disconnected. In this embodiment, the maximum width and the minimum width of the bonding layer 2 are both greater than or equal to 0.06 mm, which can avoid the bonding layer 2 from being disconnected and ensure the fixed area of ​​the bonding layer 2, the busbar and the interconnection member 3.

[0058] In some embodiments, a bonding layer 2 includes a plurality of bonding segments 21 arranged along the length direction of the interconnection member 3; along the length direction of the interconnection member 3, the length difference between any two bonding segments 21 is less than or equal to 3.8 mm.

[0059] It should be understood that the bonding layer portion corresponding to the pad position and the position within the range of 3 mm to 7.5 mm near the pad can be divided into bonding segments 21. Adjacent bonding segments 21 can be spaced apart or connected together. Figure 2 When adjacent bonding segments 21 are connected together, the narrowest position of the bonding layer 2 between two bonding segments 21 or the midpoint position between two bonding segments 21 can be used as the boundary position of the bonding segments 21. At this time, the lengths of each bonding segment 21 are relatively uniform, which can provide a uniform fixing force for the confluence portion and the interconnection member 3, reducing the problem of partial pull-off.

[0060] In some embodiments, along the length direction of the interconnection member 3, the length X of the bonding segment 21 is greater than or equal to 3 mm and less than or equal to 7.5 mm. The length X of the bonding segment 21 can be 3 mm, 4 mm, 5 mm, 6 mm, 6.8 mm, 7.5 mm, etc. The length X of the bonding segment 21 is preferably 4 mm-6.8 mm. When the length of the bonding segment 21 is within the above range, the bonding layer can provide an effective fixing effect. When the length is less than this range, it cannot be ensured that the bonding layer 2 effectively fixes the conduit and the interconnection member 3. When the length exceeds this range, the material loss is large and the effective utilization rate of the bonding layer 2 is low.

[0061] In some embodiments, the number of bonding segments 21 is N, N is greater than or equal to Y / 2X, Y is the length of the battery cell 1, in mm; X is the length of the bonding segment 21, in mm. N is greater than or equal to Y / 2X, that is, N×X is greater than or equal to Y / 2, that is, the total length of a single bonding layer 2 composed of multiple bonding segments 21 is greater than or equal to half the length of the battery cell 1. The number of bonding segments 21 can be used as the design number of solder paste dots for making the bonding layer 2. At this time, the number is designed according to the length of the solder paste dots after extension in actual production, that is, the length of the bonding segment 21, which can take into account both bonding performance and cost.

[0062] It should be noted that, when the lengths of the various joining segments 21 are equal, X is the length of a single joining segment 21 ; when the lengths of some joining segments 21 are unequal, X may be the average length of the plurality of joining segments 21 .

[0063] In some embodiments, the busbar includes a pad 111, and along the width direction of the interconnection member 3, the width of the pad 111 is greater than or equal to the width of the interconnection member 3, and the width of the pad 111 is greater than or equal to the width of the bonding layer 2. The width of the pad 111 is greater than or equal to the width of the interconnection member 3, so that the entire width area of ​​the interconnection member 3 can be connected to the pad 111. The pad 111 serves as a connection base for the bonding layer 2 and the interconnection member 3 on the battery cell 1. When the width of the pad 111 is large, the fixing effect of the interconnection member 3 and the bonding layer 2 on the battery cell 1 can be improved.

[0064] In some embodiments, an interconnection member 3 connects two battery cells 1; along the length direction of the interconnection member 3, the length of the bonding layer 2 attached to the surface of the interconnection member 3 is greater than or equal to 85% of the sum of the lengths of the two battery cells 1. The interconnection member 3 effectively fixes the two battery cells 1 through the bonding layer 2. When the length of the bonding layer 2 attached to the surface of the interconnection member 3 is greater than or equal to 85% of the sum of the lengths of the two battery cells 1, the effective fixing length of the interconnection member 3 and the two battery cells 1 is greater than or equal to 85% of the sum of the lengths of the two battery cells 1, which can not only effectively fix one battery cell 1, but also reliably fix two battery cells 1, thereby ensuring the reliability of the electrical connection of the battery string and the assembly.

[0065] In some embodiments, the bus portion is a bus electrode 11 , the bus electrode 11 is wavy, and the lower surface of the bonding layer 2 is wavy.

[0066] The bus electrode 11 is preferably wavy along its length. An insulating member 13 is disposed between the bus electrode 11 and the opposite collector electrode 12 . The bus electrode 11 includes a suspension portion 113 located above the insulating member 13 . The bonding layer 2 includes a bonding suspension portion 22 located above the suspension portion 113 .

[0067] When the bus electrode 11 is wavy and the lower surface of the bonding layer 2 is wavy, the contact area between the bus electrode 11 and the bonding layer 2 can be increased, thereby improving the fixing effect of the bus electrode 11 and the bonding layer 2 .

[0068] In some embodiments, the bus portion is a bus electrode 11 , and an insulating member 13 is provided between the bus electrode 11 and a collector electrode 12 of opposite polarity along a height direction of the bus electrode 11 .

[0069] The insulating member 13 may be an insulating glue. The width of the insulating member 13 is greater than the width of the collector electrode 12. Along the width direction of the interconnection member 3, the length of the insulating member 13 is greater than the width of the interconnection member 3. The shape of the insulating member 13 may be a square, a square with rounded corners, a trapezoid, a waist shape, an ellipse, etc. The insulating member 13 can achieve insulation between the bus electrode 11 and the collector electrode 12 of opposite sex.

[0070] In this embodiment, when preparing the battery cell 1, the collecting electrode 12 is first printed on the battery cell body 14, then the insulating glue is printed on the collecting electrode 12, and finally the bus electrode 11 is printed on the battery cell body 14. After printing, the pad 111 and the connecting wire 112 in the bus electrode 11 are electrically connected to the collecting electrode 12 of the same polarity.

[0071] In some embodiments, the bus portion is a bus electrode 11, and a plurality of insulating members 13 are arranged along the length direction of the bus electrode 11. In order to ensure the continuity of the bus electrode 11, the bus electrode 11 will cover the plurality of insulating members 13 arranged along the length direction thereof, and at this time, the bus electrode 11 includes a suspension portion 113 located above the insulating member 13, and the bonding layer 2 includes a bonding suspension portion 22 located above the suspension portion 113.

[0072] Reference Figure 4 , the height of the suspended portion 113 of the bus electrode 11 located above the insulating member 13 is less than the height of the other portions of the bus electrode 11 except the suspended portion 113 ; the height of the bonding suspended portion 22 of the bonding layer 2 located above the suspended portion 113 is less than the height of the other portions of the bonding layer 2 except the bonding suspended portion 22 .

[0073] The other parts of the bus electrode 11 except the suspended part 113 are the main conductive parts, therefore, the height of the other parts of the bus electrode 11 except the suspended part 113 is relatively large to ensure the overall conductive performance of the bus electrode 11. In addition, the height of the suspended part 113 is less than the height of the other parts of the bus electrode 11 except the suspended part 113, which can save the material consumption of the bus electrode 11 while ensuring the continuity of the bus electrode 11.

[0074] In some embodiments, the height of the joint suspension portion 22 is greater than the height of the suspension portion 113 of the bus electrode 11. In this case, the joint suspension portion 22 can provide a greater fixing force for the suspension portion 113 of the bus electrode 11 and the interconnection member 3.

[0075] In some embodiments, the width of the collector electrode 12 is greater than or equal to 25 micrometers and less than or equal to 70 micrometers. The busbar portion is the busbar electrode 11, and the width of the connecting line 112 included in the busbar electrode 11 is 70 micrometers to 140 micrometers.

[0076] The width of the collector electrode 12 may be 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, etc. The width of the collector electrode 12 is preferably 30 μm-40 μm. The width of the collector electrode 12 of the positive electrode is greater than that of the collector electrode 12 of the negative electrode. The width of the collector electrode 12 of the positive electrode may be 40 μm, and the width of the collector electrode 12 of the negative electrode may be 30 μm.

[0077] The width of the connecting wire 112 can be 70 μm, 80 μm, 100 μm, 110 μm, 130 μm, 140 μm, etc. The width of the connecting wire 112 is preferably 100 μm. When the width of the connecting wire 112 is within the above range, the width of the connecting wire 112 is narrow, which can reduce the amount of slurry used in the bus electrode 11 while ensuring current transmission, thereby reducing the cost of the photovoltaic module. At the same time, the width of the connecting wire 112 is greater than the collecting electrode 12, which can reduce the loss of the current collected by the collecting electrode 12 on the connecting wire 112.

[0078] In some embodiments, the main material of the busbar and the collector electrode 12 is selected from silver, copper, aluminum or nickel.

[0079] The main material of the confluence part and the collector electrode 12 is the material that accounts for more than 50% of the mass of the materials of the confluence part and the collector electrode 12. The main material of the confluence part and the collector electrode 12 is any one of silver, copper, aluminum, and nickel. When the main material of the confluence part is copper, it can play a role in grasping the bonding layer 2 and can effectively reduce the cost.

[0080] When the main material of the busbar and the collector electrode 12 is selected from copper, silver, silver-copper alloy, and silver-clad copper, the copper or silver is specifically low-temperature copper paste or low-temperature silver paste. The printing process of the busbar and the collector electrode 12 can be screen printing. The welding method of the busbar and the interconnection member 3 can be low-temperature infrared welding.

[0081] In the fixing scheme of the related technology interconnection component and the battery cell, the main material of the solder layer of the interconnection component is tin, the busbar portion adopts a busbar electrode, and the main material of the connecting wire is silver. The interconnection component is welded to 7 pads in the busbar electrode through 7 conductive glue points. After a pull-off test and EDS (Energy Dispersive Spectroscopy) analysis, no tin component was detected in the remaining part of the connecting wire, and the silver content was relatively high, indicating that the connecting wire failed to form an effective connection with the interconnection component.

[0082] In the fixing scheme of the interconnection component and the battery cell of this embodiment, the material of the solder layer of the interconnection component 3 is tin, and the bus electrode 11 is used. The main material of its connecting wire 112 is silver. When the number of the first bonding segments 23 is 21, the interconnection component 3 is subjected to a pull-off test. After EDS analysis, the silver content of the remaining part of the connecting wire 112 is greatly reduced, and the tin component is detected in the remaining part of the connecting wire 112, indicating that the connecting wire 112 is fully pulled off, that is, the bonding strength and fixing effect of the connecting wire 112 and the interconnection component 3 are good.

[0083] The interconnection stripping test was conducted on the fixing scheme of the interconnection parts and the battery cell of the related technology and the fixing scheme of the interconnection parts and the battery cell of this embodiment, and the stripping force data of the interconnection parts were collected. After analyzing the stripping force data of the interconnection parts, it was found that compared with the solution of the related technology, the average stripping force of the interconnection parts in the P area of ​​the solution provided by this embodiment increased by 0.35N, and the qualified rate increased by 24%. The average stripping force of the interconnection parts in the N area increased by 0.57N, and the qualified rate increased by 29%. The stripping force size and average value of the interconnection parts are significantly better than those of the related technology solutions, which significantly improves the welding quality. Among them, the stripping force of the interconnection parts refers to the force required to strip the interconnection parts from the battery cell.

[0084] The photovoltaic modules using the related art interconnection and battery cell fixing scheme and the interconnection and battery cell fixing scheme of this embodiment were tested, and CTM data were collected. After analyzing the CTM data, it was found that for batteries of different efficiencies, the CTM data of the scheme provided by this embodiment were improved compared with the related art scheme, and the CTM data were improved by an average of about 0.14%.

[0085] In summary, through experimental analysis, it can be known that the photovoltaic assembly provided by the implementation of the present invention can effectively improve the bonding force and fixing effect between the interconnection member 3 and the busbar, can improve the pull-off force between the interconnection member 3 and the busbar, and can improve the CTM data.

[0086] An embodiment of the present invention further provides a photovoltaic system, which includes a photovoltaic component according to any one of the above embodiments or a combination of multiple embodiments.

[0087] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0088] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A photovoltaic module, characterized in that: It includes a battery cell and an interconnection member, wherein the battery cell has a busbar, and the interconnection member connects the busbars on adjacent battery cells; The busbar and the interconnection member are fixed and electrically connected via a bonding layer; On the surface of the battery sheet, the bonding layer is fixed to an interconnection member over more than 60% of its length.

2. The photovoltaic module according to claim 1, characterized in that: On the surface of the battery cell, the bonding layer is fixed to an interconnection member over more than 82% of its length.

3. The photovoltaic module according to claim 1, characterized in that: The bus portion is a bus electrode extending in the same direction as the interconnection member, and the bonding layer is fixed to more than 70% of the bus electrode along its length direction; Or the battery cell further has a collector electrode, and the confluence portion is arranged on the collector electrode; Or the confluence portion is a multi-segment electrode.

4. The photovoltaic module according to claim 1, characterized in that: The busbar portion includes a plurality of pads, and a peeling force between more than 80% of the pads in the busbar portion and the interconnection member is greater than or equal to 1N.

5. The photovoltaic module according to claim 1, characterized in that: Between the busbar and the interconnector, the bonding layer is in a strip shape; And / or, the bonding layer comprises at least one independent bonding layer segment, and the bonding layer segment has a length greater than a width.

6. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The battery cell also has a collector electrode; On a battery cell, a plurality of M positions are provided on the busbar corresponding to an interconnector, wherein the M positions are intersection positions of the busbar and the collector electrode, and at least 10 of the M positions have intermetallic compounds.

7. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The battery cell also has a collector electrode; The collector electrode has a plurality of M positions, wherein the M positions are intersection positions of the collector electrode and the confluence portion, and 3 to 14 M positions on each of the collector electrodes have intermetallic compounds, and / or the collector electrode is a continuous collector electrode.

8. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The battery cell also has a collector electrode, at least one of the collector electrodes is in direct contact with the bonding layer, and the collector electrode is electrically connected to the interconnection member through the bonding layer.

9. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The bonding layer comprises a first bonding segment and a second bonding segment, wherein the width of the first bonding segment is greater than the width of the second bonding segment; The first bonding segment fixes the bottom of the interconnection member and at least part of the side surface of the interconnection member, and the second bonding segment fixes the bottom of the interconnection member; and / or, there is a second bonding segment between two adjacent first bonding segments.

10. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The bonding layer and the confluence portion form an intermetallic compound; The intermetallic compound formed by the bonding layer and the busbar includes a portion A and a portion B. Along the width direction of the interconnect, the width of the portion A is greater than the width of the portion B.

11. The photovoltaic module according to claim 10, characterized in that: along the length direction of the interconnection element; There is a B portion between two adjacent A portions; and / or, at least one of the A portions is closer to the end of the interconnecting member than the B portion; and / or, one A portion is connected to one B portion.

12. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The maximum width of the bonding layer is less than or equal to 1.2 mm and greater than or equal to 0.06 mm; The minimum width of the bonding layer is greater than or equal to 0.06 mm and less than or equal to 1.2 mm.

13. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The bonding layer includes a plurality of bonding segments arranged along the length direction of the interconnection element; Along the length direction of the interconnection member, the length difference between any two of the joining segments is less than or equal to 3.8 mm; and / or, along the length direction of the interconnection member, the length X of the joining segment is greater than or equal to 3 mm and less than or equal to 7.5 mm; and / or, the number of the joining segments is N, N is greater than or equal to Y / 2X, Y is the length of the battery cell, in mm; X is the length of the joining segment, in mm.

14. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The busbar includes a pad. Along the width direction of the interconnection member, the width of the pad is greater than or equal to the width of the interconnection member, and the width of the pad is greater than or equal to the width of the bonding layer.

15. The photovoltaic module according to any one of claims 1 to 5, characterized in that: An interconnection element connects two battery cells; Along the length direction of the interconnection member, the length of the bonding layer attached to the surface of the interconnection member is greater than or equal to 85% of the sum of the lengths of the two battery cells.

16. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The busbar portion is a busbar electrode, the busbar electrode is wavy, and the lower surface of the bonding layer is wavy.

17. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The busbar portion is a busbar electrode. The battery cell also has a collector electrode. The collector electrode is a continuous collector electrode. An insulating member is provided between the busbar electrode and the collector electrode of opposite sex along the height direction of the busbar electrode.

18. The photovoltaic module according to claim 17, characterized in that: The height of the suspended portion of the bus electrode located above the insulating member is smaller than the height of other portions of the bus electrode except the suspended portion; the height of the joint suspended portion of the joint layer located above the suspended portion is smaller than the height of other portions of the joint layer except the joint suspended portion; And / or, a height of the bonding suspension portion in the bonding layer located above the suspension portion is greater than a height of the suspension portion of the bus electrode.

19. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The battery cell also has a collector electrode, the width of which is greater than or equal to 25 microns and less than or equal to 70 microns; And / or, the busbar portion is a busbar electrode, the busbar electrode includes a pad and a connecting line electrically connected together, and the width of the connecting line is 70 micrometers-140 micrometers.

20. The photovoltaic module according to any one of claims 1 to 5, characterized in that: The battery cell also has a collector electrode, and the main material of the busbar and the collector electrode is selected from silver, copper, aluminum or nickel.

21. A photovoltaic system, characterized in that: A photovoltaic module comprising any one of claims 1-20.

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