Photovoltaic module and photovoltaic system

Abstract

The invention discloses a photovoltaic module and a photovoltaic system, the photovoltaic module comprises battery pieces and interconnecting pieces, the battery pieces are provided with electrodes, the interconnecting pieces are connected in series with the adjacent battery pieces, and the interconnecting pieces and the electrodes are fixed and electrically connected through conductive material layers; at least one side, along the first direction, of the interconnector is adhered with an adhesive, and the adhesive is located on one side, deviating from the battery piece, of the conductive material layer and adheres the interconnector and the conductive material layer. According to the photovoltaic module provided by the embodiment of the invention, the bonding substance plays a role in bonding and further fixing the interconnecting piece and the conductive material layer, and the fixing effect between the interconnecting piece and the conductive material layer can be improved, so that the fixing effect between the interconnecting piece and the battery piece can be improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a photovoltaic module and a photovoltaic system. Background Technology

[0002] Photovoltaic modules consist of solar cells and solder strips, which are used to interconnect the solar cells.

[0003] In related technologies, the grid lines, or electrodes, on the solar cell are fixedly connected to the solder strip by welding.

[0004] Among the above-mentioned methods of fixing the battery cells and the solder ribbon, the fixing effect of the solder ribbon and the battery cells is limited. Summary of the Invention

[0005] This invention provides a photovoltaic module and a photovoltaic system, aiming to at least solve the technical problem of limited fixation effect of solder ribbon and solar cell in the prior art.

[0006] This invention provides a photovoltaic module, including solar cells and interconnects. The solar cells have electrodes, and the interconnects are connected in series with adjacent solar cells. The interconnects and the electrodes are fixed and electrically connected through a conductive material layer.

[0007] An adhesive is adhered to at least one side of the interconnect along a first direction. The adhesive is located on the side of the conductive material layer opposite to the battery cell and bonds the interconnect to the conductive material layer. The first direction is perpendicular to both the extension direction and the thickness direction of the interconnect.

[0008] In this embodiment of the invention, the interconnecting element and the electrode of the battery cell are fixed and electrically connected by a conductive material layer. An adhesive is adhered to at least one side of the interconnecting element along the first direction. The adhesive serves to bond and further fix the interconnecting element and the conductive material layer, thereby improving the fixing effect between the interconnecting element and the conductive material layer, and thus improving the fixing effect between the interconnecting element and the battery cell.

[0009] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the connection between solar cells and interconnects in a photovoltaic module provided in an embodiment of the present invention. Figure 1 ;

[0011] Figure 2 This is a schematic diagram of the connection between solar cells and interconnects in a photovoltaic module provided in an embodiment of the present invention. Figure 2 ;

[0012] Figure 3 This is a schematic diagram of the structure of the solar cell, conductive material layer, and residual organic matter in the photovoltaic module provided in an embodiment of the present invention;

[0013] Figure 4 This is a partial structural diagram of a solar cell in a photovoltaic module provided by an embodiment of the present invention;

[0014] Figure 5 This is a partial structural diagram of another type of solar cell in a photovoltaic module provided in an embodiment of the present invention.

[0015] Figure label:

[0016] 1-Battery cell, 11-Fine grid electrode, 111-Connector, 112-Fine wire, 12-Bucket electrode, 2-Interconnector, 3-Conductive material layer, 4-Adhesive, 41-Protrusion, 42-Recess, 5-Insulator. Detailed Implementation

[0017] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0018] Reference Figures 1 to 3 This invention discloses a photovoltaic module, including a solar cell 1 and an interconnect 2. The solar cell 1 has an electrode, and the interconnect 2 is connected in series with adjacent solar cells 1. The interconnect 2 and the electrode are fixed and electrically connected by a conductive material layer 3. An adhesive 4 is adhered to at least one side of the interconnect 2 along a first direction. The adhesive 4 is located on the side of the conductive material layer 3 away from the solar cell 1 and adheres the interconnect 2 to the conductive material layer 3.

[0019] Among them, solar cell 1 can be a back contact (BC) solar cell. For example... Figures 1 to 3 As shown, when the battery cell 1 is a back-contact battery cell and the back side of the battery cell 1 faces upwards, the conductive material layer 3 is on the side away from the battery cell 1, that is, the top side of the conductive material layer 3. As an example, the battery cell 1 is... Figure 1 and Figure 4 The diagram shows a back-contact solar cell without a main grid. As another example, cell 1 is... Figure 2 , Figure 3 and Figure 5The image shows a back-contact solar cell with a main grid. The solar cell can also be a TOPcon (Tunnel Oxide Passivated Contact) solar cell or other types of solar cells.

[0020] The first direction is perpendicular to the extension direction of the interconnecting member 2 and also perpendicular to the thickness direction of the interconnecting member 2. The first direction can be referenced... Figure 1 and Figure 2 The direction indicated by arrow A in the middle, and the extension direction of interconnect 2 can be referenced. Figure 1 and Figure 2 The direction indicated by arrow B. Interconnector 2 can be a solder ribbon, coated solder ribbon, conductive backplane, etc. The solder ribbon can be a flat solder ribbon or a round wire solder ribbon, and can also be set to other shapes according to actual needs. Interconnector 2 has a tin alloy layer. When interconnector 2 is a flat solder ribbon, the first direction is also the width direction of interconnector 2. The cross-sectional shape of the round wire solder ribbon is circular, and when interconnector 2 is a round wire solder ribbon, the first direction is also the radial direction of interconnector 2. The lower edge of the round wire solder ribbon and the flat solder ribbon often have bonding problems relative to the middle part. Adhesive 4 can be filled to enhance the edge bonding strength. Since the gap between the edge of the round wire solder ribbon and the battery cell 1 is larger and the bonding strength is weaker than that between the flat solder ribbon and the battery cell 1, filling the edge of the round wire solder ribbon with more adhesive 4, that is, some adhesive 4 is located below the interconnector 2, can enhance the bonding strength of the round wire solder ribbon. At this time, the maximum width of the adhesive 4 within the orthographic projection range of the round wire solder ribbon can be more than 10% and less than 50% of the solder ribbon diameter.

[0021] The interconnect 2 is soldered to the electrode via a conductive material layer 3. The conductive material layer 3 is made of a conductive material, primarily a metallic material such as tin. The electrode can be provided with pads, thickened sections, and other connecting parts 111, facilitating the placement of the conductive material layer 3 on the connecting parts 111 with a large surface area. The adhesive 4 is an organic material with adhesive properties, and its components include resin-based organic materials, such as rosin. The rosin can be hydrogenated rosin, modified rosin, etc. The adhesive 4 melts upon heating and is solid at room temperature. As one example, the interconnect 2 is adhered to only one side along the first direction with the adhesive 4. As another example, the interconnect 2 is adhered to both sides along the first direction with the adhesive 4.

[0022] The interconnecting component 2 is welded to the battery cell 1 using infrared welding, lamination welding, etc. The interconnecting component 2 can be welded to the battery cell 1 via a conductive material layer 3 (or other connection methods). The conductive paste C is primarily composed of a mixture of conductive materials and organic substances. The conductive material is a metallic material, such as tin, and can be in granular form. The organic substances include rosin, such as hydrogenated rosin, modified rosin, etc. The organic substances may also include reducing agents, solvents, and modifiers, such as tripropylene glycol, malonic acid, etc. After the conductive paste C is printed onto the battery cell 1 and heated, the conductive material melts to form the conductive material layer 3, and the organic substances separate and precipitate to form the binder 4. It should be understood that the ratio of metallic materials to rosin in the conductive paste C needs to be controlled at this stage.

[0023] When the interconnecting component 2 is soldered to the battery cell 1 using conductive paste C, multiple conductive pastes C are first printed onto the battery cell 1 through a screen printing plate. Then, the multiple conductive pastes C are dried and heated to cure. During the drying and heating process, conductive materials agglomerate, and at least some organic matter precipitates. After the multiple conductive pastes C are dried and heated, refer to... Figure 3 The conductive materials aggregated in multiple conductive pastes C form multiple conductive material layers 3 respectively. The organic matter precipitated from each conductive paste C forms an adhesive. Then, the interconnect 2 is welded to the battery cell 1 by infrared welding. During the welding process, the tin alloy layer of the interconnect 2 combines with the conductive material in the conductive material layer 3 to form an intermetallic compound. Multiple adhesives 4 are heated and melted again and adhered to at least one side of the interconnect 2 along its first direction.

[0024] When the conductive paste C is dried and heated, it can be heated by a heating rod, and the heating temperature can be in the range of 140℃-160℃. When the interconnecting component 2 is welded to the battery cell 1, it can be heated by an infrared lamp, and the heating temperature can be in the range of 180℃-220℃. The temperature is relatively low to prevent the rosin from carbonizing and losing its activity at high temperatures.

[0025] In this embodiment, by controlling the composition of the organic matter in the conductive paste C, the heating temperature during the drying and heating of the conductive paste C, the heating temperature during the welding of the interconnect 2 and the battery cell 1, and the shape and size of the conductive paste C, an adhesive 4 can be formed on the side of the conductive material layer 3 facing away from the battery cell 1 and on at least one side of the interconnect 2 along the first direction, bonding the interconnect 2 and the conductive material layer 3. The conductive paste C can be square, a square with rounded corners, trapezoidal, oblong, elliptical, circular, etc. Along the first direction, the length of the conductive paste C is greater than the width of the interconnect 2.

[0026] It should be noted that, through experimental verification, using only flux to weld the solder ribbon to the battery cell results in virtually no adhesive residue 4 forming. It should also be noted that if the composition of the organic matter in the conductive paste C, the heating temperature during the drying and heating of the conductive paste C, the heating temperature during the welding of the interconnect 2 to the battery cell 1, and the shape and size of the conductive paste C, do not meet specific conditions, it is virtually impossible to achieve the formation of adhesive residue 4 on the side of the conductive material layer 3 facing away from the battery cell 1, and on at least one side of the interconnect 2 along the first direction, thus bonding the interconnect 2 to the conductive material layer 3.

[0027] In this embodiment, the interconnecting component 2 and the electrode of the battery cell 1 are fixed and electrically connected by a conductive material layer 3. An adhesive 4 is adhered to at least one side of the interconnecting component 2 along the first direction. The adhesive 4 serves to bond and further fix the interconnecting component 2 and the conductive material layer 3, thereby improving the fixing effect between the interconnecting component 2 and the conductive material layer 3, and thus improving the fixing effect between the interconnecting component 2 and the battery cell 1.

[0028] In some embodiments, refer to Figure 1 and Figure 2 The interconnecting component 2 has adhesive 4 adhered to both sides along the first direction. In this embodiment, the interconnecting component 2 is bonded to both sides along the first direction with the aid of adhesive 4, resulting in a more balanced fixing force on both sides of the interconnecting component 2 and a more balanced stress, which can reduce the warping of the interconnecting component 2.

[0029] In some embodiments, refer to Figure 1 On one side of the battery cell 1, the electrodes include alternating first and second fine grid electrodes, with an isolation region between the first and second fine grid electrodes; the interconnect 2 is connected to the first fine grid electrode through a conductive material layer 3, and an insulating member 5 is provided between the interconnect 2 and the second fine grid electrode; along the extending direction of the interconnect 2, at least one adhesive 4 bonds two adjacent conductive material layers 3, the isolation region between two adjacent conductive material layers 3, and the insulating member 5; in some embodiments, at least one adhesive 4 bonds a conductive material layer 3, an isolation region adjacent to the conductive material layer 3, and the insulating member 5.

[0030] In this embodiment, battery cell 1 is a back-contact battery cell, as shown in the reference. Figure 1 and Figure 4On one side of the battery cell 1, a first fine grid electrode and a second fine grid electrode extend along a first direction and are alternately distributed along a second direction. The interconnecting member 2 is connected to the first fine grid electrode via a conductive material layer 3, and the interconnecting member 2 is isolated from the second fine grid electrode via an insulating member 5. The first and second fine grid electrodes have opposite polarities. The second direction is parallel to the extension direction of the interconnecting member 2. The fine grid electrode 11 includes a thin wire 112 and a connecting portion 111, the width of which is greater than the width of the thin wire 112. Specifically, the connecting portion 111 on the first fine grid electrode is fixed and electrically connected to the interconnecting member 2 via the conductive material layer 3. (Refer to...) Figure 2 and Figure 3 In other back-contact cells with main grids, the adhesive 4 is similarly positioned at the end of cell 1.

[0031] Along the extension direction of the interconnect 2, the back side of the solar cell 1 has alternating P-type and N-type doped regions, separated from adjacent P-type and N-type doped regions by undoped isolation regions. The insulating component 5 can be an insulating adhesive, which can be an epoxy resin system, with epoxy resin as the main component after curing. The additives in the insulating adhesive will evaporate during the curing process, leaving no residue.

[0032] Preferably, the multiple adhesives 4 adhered to one side of the interconnect 2 along the first direction all bond to two adjacent conductive material layers 3, the isolation area between two adjacent conductive material layers 3, and the insulating element 5. Along the extension direction of the interconnect 2, the adhesives 4 adhered to one side of the interconnect 2 along the first direction can be continuous strips, or there can be several adhesives 4, which are separated by small gaps, and all the adhesives 4 bond to two adjacent conductive material layers 3, the isolation area between two adjacent conductive material layers 3, and the insulating element 5.

[0033] When at least one adhesive 4 bonds two adjacent conductive material layers 3, the isolation area between two adjacent conductive material layers 3, and the insulating component 5, the adhesive 4 has a certain length to ensure the fixing effect between the interconnect 2 and the battery cell 1. When at least one adhesive 4 bonds a conductive material layer 3, the isolation area adjacent to the conductive material layer 3, and the insulating component 5, the adhesive 4 has a certain length to ensure the fixing effect between the interconnect 2 and the battery cell 1. In this embodiment, in addition to bonding the interconnect 2 and the conductive material layer 3, the adhesive 4 also bonds the isolation area and the insulating component 5, which can further improve the fixing effect between the interconnect 2 and the battery cell 1.

[0034] In some embodiments, refer to Figure 2 , Figure 3 and Figure 5The solar cell 1 is a back-contact solar cell with a main grid. The electrodes include fine grid electrodes 11 and bus electrodes 12. The extension direction of the bus electrode 12 is consistent with the extension direction of the interconnect 2. The bus electrode 12 has pads, specifically, the pads in the bus electrode 12 are fixed and electrically connected to the interconnect 2 through a conductive material layer 3. Multiple fine grid electrodes 11 are arranged at intervals along the extension direction of the interconnect 2. Each fine grid electrode 11 includes multiple positive fine grid electrodes and multiple negative fine grid electrodes, which are arranged alternately along the extension direction of the interconnect 2. The bus electrode 12 is electrically connected to fine grid electrodes of the same polarity, and an insulating member 5 is provided between the bus electrode 12 and the fine grid electrodes 11 of opposite polarity.

[0035] In some embodiments, refer to Figure 1 and Figure 2 The electrode includes a fine gate electrode 11, and along the extending direction of the interconnect 2, at least one adhesive 4 spans at least two fine gate electrodes 11. (Refer to...) Figure 1 The adhesive 4 bonds multiple fine grid electrodes 11, interconnecting components 2, and conductive material layer 3 into a whole with the battery cell 1 as the substrate, which can ensure the bonding effect between interconnecting components 2 and conductive material layer 3.

[0036] Preferably, at least one adhesive 4 spans at least three fine gate electrodes 11. As an example, see [reference needed]. Figure 1 The solar cell 1 is a back-contact solar cell without a main grid, and at least one adhesive 4 spans at least the second grid electrode and the two first grid electrodes adjacent to the second grid electrode. As another example, refer to Figure 2 The battery cell 1 is a back-contact battery cell with a main grid, and at least one adhesive 4 spans at least the fine grid electrode 11 with the same polarity as the bus electrode 12 and two fine grid electrodes 11 adjacent to the fine grid electrode 11.

[0037] In some embodiments, at least one adhesive 4 bonds the interconnect 2 to the fine grid electrode 11. In this embodiment, the adhesive 4 not only bonds the interconnect 2 to the conductive material layer 3, but also extends and expands to bond the interconnect 2 to the fine grid electrode 11, thereby improving the connection strength of the interconnect 2 on the battery cell 1. Here, the fine grid electrode 11 includes a thickened section of the electrode, a pad, a connection portion 111, and other parts used to deposit the conductive material layer 3.

[0038] In some embodiments, at least one adhesive 4 bonds the interconnect 2 to the passivation layer on the surface of the battery cell 1. The passivation layer is located on the back side of the battery cell 1. In this embodiment, the passivation layer has a large spreading area on the battery cell 1 and a high bonding strength, making peeling problems generally difficult. When the adhesive 4 bonds the interconnect 2 to the passivation layer on the battery cell 1, the fixing effect is better than that of the electrodes.

[0039] In some embodiments, the multiple adhesives 4 are distributed in a dotted and discrete manner along the extension direction of the interconnecting member 2. The dotted and discrete distribution of the adhesives 4 can not only take into account the material loss of the adhesives 4, but also disperse the force and maximize the use of the adhesive force provided by the adhesives 4. Here, discreteness can mean that there are gaps between the adhesives 4.

[0040] In some embodiments, refer to Figure 1 The solar cell 1 is a back-contact solar cell without a main grid. The interconnect 2 includes two connecting segments that connect two adjacent solar cells 1 respectively. At least one of the connecting segments has a continuous adhesive 4 adhered to one side. It should be understood that the continuous adhesive 4 can also be provided on solar cells with main grids.

[0041] The two connecting segments are the two parts of the interconnect 2 located on two adjacent battery cells 1. The adhesive 4 adhering to the two connecting segments is spaced apart along the extension direction of the interconnect 2. Preferably, each connecting segment has a continuous adhesive 4 adhering to both sides along the first direction. In this embodiment, at least one of the two connecting segments has a continuous adhesive 4 adhering to one side. Compared with several spaced adhesives 4, the continuous adhesive 4 can adhere the interconnect 2 to the surface of the battery cell 1 as a whole, resulting in a better bonding effect on the interconnect 2. It should be understood that the length of the continuous adhesive 4 can be approximately 2 mm or longer, for example, 5 mm to 105 mm.

[0042] In some embodiments, refer to Figure 1 The edge of the adhesive 4 away from the interconnect 2 has an uneven surface. As an example, the uneven surface of the edge of the adhesive 4 is similar to a wave. In this embodiment, the edge of the adhesive 4 is smooth and wavy, which can reduce the risk of stress concentration.

[0043] In some embodiments, refer to Figure 1 The adhesive 4 protrudes at the position of the conductive material layer 3 to form a protrusion 41, and is recessed at the position of the insulating component 5 to form a recess 42.

[0044] Both the protrusion 41 and the recess 42 are arc-shaped. The width of the protrusion 41 is greater than the width of the recess 42, and the width direction is the A direction. In this embodiment, the wider protrusion 41 is located at the position of the conductive material layer 3 to ensure the bonding effect between the interconnect 2 and the conductive material layer 3, while the narrower recess 42 is located at the position of the insulating member 5, which can balance material loss and bonding effect.

[0045] In some embodiments, refer to Figure 1 and Figure 2 At least one end of the interconnecting element 2 is adhered with adhesive 4.

[0046] Along the length of the interconnect 2, the interconnect 2 has two opposing ends. Preferably, both ends of the interconnect 2 are adhered with adhesive 4. The interconnect 2 connects adjacent first and second battery cells. The first end of the interconnect 2 is bonded to the conductive material layer 3 on the first battery cell via adhesive 4, and the second end of the interconnect 2 is bonded to the conductive material layer 3 on the second battery cell via adhesive 4.

[0047] In related technologies, the ends of interconnecting components 2 are prone to warping. In this embodiment, at least one end of interconnecting component 2 is adhered with an adhesive 4, which bonds the end of interconnecting component 2 to the conductive material layer 3, thereby improving the fixing reliability of the end of interconnecting component 2 and alleviating the problem of warping at the end of interconnecting component 2.

[0048] In some embodiments, refer to Figure 1 and Figure 2 At least one end of the interconnect 2 is surrounded on three sides by an adhesive 4. In some embodiments, at least one end of the interconnect 2 extends beyond the adhesive 4 adhered to that end, and a portion of the adhesive 4 is located below the end region of the interconnect 2.

[0049] Preferably, for any end of the interconnect 2, the adhesive 4 adhering to both sides in the first direction and the adhesive 4 adhering to one end in the extension direction form a three-sided surrounding structure. When the adhesive 4 surrounds the end of the interconnect 2 on three sides, the three adhesive 4s can be integrated. For example, for any end of the interconnect 2, the two adhesives 4 adhering to both sides in the first direction extend and connect to the two ends of the adhesive 4 adhering to one end in the extension direction. When the adhesive 4 surrounds the end of the interconnect 2 on three sides, the three adhesives 4 allow for gaps caused by process errors. In this embodiment, the adhesive 4 surrounding the end of the interconnect 2 on three sides can form a surround around the end of the interconnect 2, reducing the probability of the interconnect 2 warping from the head or side, improving the fixing reliability of the end of the interconnect 2, and further improving the problem of the end of the interconnect 2 warping.

[0050] As an example, the battery cell 1 is a back-contact battery cell without a main grid. An adhesive 4 is adhered to the side of each end of the interconnect member 2 opposite to the other end of the interconnect member 2. The interconnect member 2 includes two connecting segments that connect two adjacent battery cells 1 respectively. Each connecting segment has a continuous strip-shaped adhesive 4 adhered to both sides along a first direction. Thus, one interconnect member 2 has two strip-shaped adhesives 4 adhered to one side along the first direction, spaced apart at the interval between two adjacent battery cells 1. Another interconnect member 2 has two strip-shaped adhesives 4 adhered to the other side along the first direction, also spaced apart at the interval between two adjacent battery cells 1. Two continuous adhesives 4 are adhered to both sides along the extending direction of the interconnect member 2. The width of the adhesive 4 between two adjacent battery cells 1 is greater than the width of the adhesive 4 in the middle of the battery cell 1. This improves the fixing effect of the interconnect member 2 near the interval between two adjacent battery cells 1.

[0051] As another example, the battery cell 1 is a back-contact battery cell with a main grid. An interconnect 2 is connected to two adjacent battery cells 1 through N conductive material layers 3, where N is a positive integer greater than or equal to 2. Adhesive 4 is adhered to N positions on the interconnect 2 corresponding to the N conductive material layers 3. The N positions are spaced apart along the extension direction of the interconnect 2, and the two outermost positions are the two ends of the interconnect 2. The adhesive 4 adhered to the ends of the interconnect 2 forms a three-sided surrounding structure.

[0052] In some embodiments, along the extension direction of the interconnect 2, the length of an adhesive 4 is a, and the length of the conductive material layer 3 bonded by the adhesive 4 is b; a≥b, or 0.8b≤a≤4.3b, or 1.15b≤a≤3.3b. The length direction is consistent with the extension direction of the interconnect 2.

[0053] As an example, 'a' can be any value among 0.8b, b, 1.1b, 1.15b, 2b, 3.3b, 3.5b, 4b, and 4.3b. For the independent conductive material layer 3, the adhesive 4 that bonds the conductive material layer 3 and the interconnect 2 is longer, which allows the conductive material layer 3 to be bonded and fixed to the interconnect 2 over a longer range. It can also cover the edge of the conductive material layer 3 or the junction with the battery cell 1, thereby improving the fixation effect of the conductive material layer 3 itself on the battery cell 1.

[0054] In some embodiments, refer to Figure 2 For an interconnect 2 located on a battery cell 1, multiple adhesives 4 are spaced apart along its extension direction, and the length of a single adhesive 4 can be greater than the length of a single conductive material layer 3.

[0055] In some embodiments, refer to Figure 1Along the extension direction of the interconnect 2, the interconnect 2 has an X portion located on a battery cell 1, the length of the adhesive 4 corresponding to one side of the X portion is m, the length of the corresponding conductive material layer is m, m>n; or, 1.5n≤m≤4n.

[0056] As an example, m can be equal to any value among 1.1n, 1.5n, 2n, 2.5n, 3n, and 4n. For example, for the X portion of an interconnect 2 located on a battery cell 1, the length of the adhesive 4 along its extension direction is either the length of the continuous adhesive 4 or the sum of the lengths of the discrete adhesive 4.

[0057] Multiple conductive material layers 3 are arranged at intervals along the extension direction of the interconnect 2. The length of the conductive material layer 3 connected to the interconnect 2 on a battery cell 1 is the sum of the lengths of the multiple conductive material layers 3 connected to the interconnect 2 on the battery cell 1. Preferably, the length of the adhesive 4 is more than 1.5 times the length of the conductive material layer 3. The length of the adhesive 4 is less than or equal to 4 times the length of the conductive material layer 3. In this embodiment, the adhesive 4 adhered to the interconnect 2 on the battery cell 1 is relatively long, and the adhesion area of ​​the adhesive 4 is relatively large. The adhesive 4 not only bonds the interconnect 2 to the conductive material layer 3, but also bonds more of the non-conductive material layer portion of the surface of the interconnect 2 to the battery cell 1, thereby improving the fixing effect between the interconnect 2 and the battery cell 1.

[0058] In some embodiments, refer to Figure 1 Along the extending direction of the interconnect 2, the length of the adhesive 4 adhering to a portion of the interconnect 2 on a battery cell 1 is less than the length of that portion of the interconnect 2, and the length difference is between 2mm and 18mm.

[0059] The length of this portion of the interconnect 2 is the length of the part of the interconnect 2 located on a battery cell 1. As an example, the difference between the length of the adhesive 4 adhering to the portion of the interconnect 2 located on a battery cell 1 and the length of this portion of the interconnect 2 can be 2mm, 3mm, 4mm, 5mm, 10mm, 15mm, 18mm, etc. Preferably, the difference between the length of the adhesive 4 adhering to the portion of the interconnect 2 located on a battery cell 1 and the length of this portion of the interconnect 2 is less than or equal to 5mm. In this embodiment, the portion of the interconnect 2 located on a battery cell 1 is fixed with adhesive 4 for most of its length, thereby ensuring that most of the interconnect 2 is fixed by both welding and bonding, which improves the fixing effect of the interconnect 2.

[0060] In some embodiments, at the same location on the interconnecting member 2, the widths of the two adhesives 4 adhering to both sides of the interconnecting member 2 along the first direction are unequal. In this embodiment, while ensuring the bonding effect between the interconnecting member 2 and the conductive material layer 3, it is not required that the widths of the two adhesives 4 adhering to both sides of the interconnecting member 2 along the first direction at the same location on the interconnecting member 2 be equal. This reduces the placement accuracy requirements of the interconnecting member 2 and improves welding efficiency.

[0061] In some embodiments, the width of the adhesive 4 adhering to one side of the interconnect 2 along the first direction is less than or equal to 1.8 times the width of the interconnect 2. Preferably, the width of the adhesive 4 adhering to one side of the interconnect 2 along the first direction is less than or equal to the width of the interconnect 2. In this embodiment, the width of the adhesive 4 adhering to one side of the interconnect 2 along the first direction can effectively cover the conductive material layer 3, and can avoid material waste caused by excessively wide adhesive 4.

[0062] In some embodiments, along the first direction, the adhesive 4 protrudes beyond the conductive material layer 3 by a size where the size of the conductive material layer 3 is 1:(1.6-12). Alternatively, along the first direction, the size of the adhesive 4 protruding beyond the conductive material layer 3 can be 1:1.6, 1:2, 1:2.5, 1:3, 1:3.8, 1:4, 1:5, 1:6, 1:10, 1:12, etc. In this embodiment, the portion of the adhesive 4 protruding beyond the conductive material layer 3 along the first direction has an appropriate protrusion width, which improves the adhesion effect of the adhesive 4 to the edge of the conductive material layer 3.

[0063] In some embodiments, along the thickness direction of the battery cell 1, the top of the adhesive 4 is not lower than one-quarter of the height of the interconnect 2. The one-quarter height position of the interconnect 2 is also the location where one-quarter of the interconnect 2's height is situated. Along the thickness direction of the battery cell 1, the top of the adhesive 4 is lower than the top surface of the interconnect 2 facing away from the battery cell 1. In this embodiment, the adhesive 4 has an appropriate thickness to ensure that the side of the interconnect 2 is fixed to the battery cell 1, and the adhesive 4 within this height range is relatively easy to manufacture.

[0064] In some embodiments, the adhesive 4 comprises rosin.

[0065] The main component of the binder 4 is rosin, which can be hydrogenated rosin, modified rosin, etc. Hydrogenated rosin is preferred, as it is more easily precipitated during the heating process of the conductive paste C. The rosin in the conductive paste C is a good flux, enhancing the welding effect between the interconnect 2 and the conductive material layer 3. The binder 4 also includes hydrogenated castor oil. In this embodiment, the rosin and hydrogenated castor oil precipitated from the conductive paste C after heating and welding the interconnect 2 to the battery cell 1 under specific conditions are used as the binder 4. This eliminates the need for additional bonding materials, saving steps and improving the fixation effect of the interconnect 2.

[0066] In some embodiments, the interconnect 2 has a position A and a position B, where position A is the end of the interconnect 2 and position B is the area outside the end of the interconnect 2. At position A, the adhesive 4 bonds at least the interconnect 2 and the electrode. At position B, the adhesive 4 bonds the interconnect 2, the conductive material layer 3, and the electrode. At position B, the adhesive 4 bonds the electrode in addition to bonding the interconnect 2 and the conductive material layer 3, which can further improve the fixing effect between the interconnect 2 and the battery cell 1. At position A, an independent adhesive 4 that does not rely on the conductive material layer 3 can be provided. Using this separately provided adhesive 4 to fix the interconnect 2 and the electrode can enhance the fixing and anti-shaking effect of the end of the interconnect 2.

[0067] In some embodiments, the two ends of the interconnect 2 connecting adjacent battery cells 1 have different shapes and sizes of adhesives 4; and / or, the interconnect 2 connecting adjacent battery cells 1 includes a first segment located on the preceding battery cell 1 and a second segment located on the following battery cell 1, and the shape of the adhesive 4 on the side of the first segment of the interconnect 2 is the same as the shape of the adhesive 4 on the side of the second segment.

[0068] Among them, the dimensions of the adhesive 4 at both ends of the interconnect 2 include the length, width, and thickness of the adhesive 4. At this time, the fixing method of the adhesive 4 to the interconnect 2 can be designed according to the electrode design at both ends of the interconnect 2 and the edge condition of the battery cell 1. It can be a surround type or a fixation on both sides.

[0069] The shape of the adhesive 4 on the first side of the interconnecting component 2 is the same as the shape of the adhesive 4 on the second side, but the size can differ, that is, dimensional errors are allowed. For example, both can be wavy, but the size of the wave undulations can be different. The shape of the adhesive 4 on the first side of the interconnecting component 2 is the same as the shape of the adhesive 4 on the second side to ensure that the fixing effect of the interconnecting component 2 with the previous battery cell 1 and the next battery cell 1 is basically the same.

[0070] In some embodiments, the solar cell 1 is a back-contact solar cell without a main grid. This solar cell eliminates the main grid lines, which saves on the paste consumed by the main grid lines, and has no electrode obstruction on the front side, resulting in low light loss and an aesthetically pleasing appearance.

[0071] In this embodiment, the electrode includes a first fine grid electrode and a second fine grid electrode. On one side of the battery cell 1, the first fine grid electrode and the second fine grid electrode extend along a first direction and are alternately distributed along a second direction. The interconnecting member 2 is connected to the connection portion 111 on the first fine grid electrode through a conductive material layer 3. The interconnecting member 2 is isolated from the second fine grid electrode below it by an insulating member 5 or the second fine grid electrode below the interconnecting member 2 is interrupted.

[0072] When the solar cell 1 is a gridless back-contact solar cell, more than 80% of the connection portions 111 (the positions where the interconnection member 2 is connected) on the fine grid electrode 11 through which the interconnection member 2 passes are provided with a conductive material layer 3 and an adhesive 4. The adhesive 4 on both sides of the interconnection member 2 is densely arranged and can be easily connected into a wavy line. Compared with the solar cell 1 with 6-10 connection portions 111, the gridless back-contact solar cell 1 has more adhesive 4 and a better bonding effect.

[0073] This invention also provides a photovoltaic system, which includes photovoltaic modules of any or a combination of the above embodiments.

[0074] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0075] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the present invention, and all of these modifications are within the protection scope of the present invention.

Claims

1. A photovoltaic module, characterized in that, It includes battery cells and interconnects, wherein the battery cells have electrodes, the interconnects are connected in series with adjacent battery cells, and the interconnects are fixed and electrically connected to the electrodes through a layer of conductive material; An adhesive is adhered to at least one side of the interconnect along a first direction. The adhesive is located on the side of the conductive material layer opposite to the battery cell and bonds the interconnect to the conductive material layer. The first direction is perpendicular to both the extension direction and the thickness direction of the interconnect.

2. The photovoltaic module according to claim 1, characterized in that, The adhesive is adhered to both sides of the interconnecting component along the first direction.

3. The photovoltaic module according to claim 1, characterized in that, On one side of the battery cell, the electrode includes an alternately distributed first fine grid electrode and a second fine grid electrode, with an isolation region between the first fine grid electrode and the second fine grid electrode; the interconnect is connected to the first fine grid electrode through the conductive material layer, and an insulating element is provided between the interconnect and the second fine grid electrode; Along the extension direction of the interconnect, at least one of the adhesives bonds two adjacent conductive material layers, the isolation region between the two adjacent conductive material layers, and the insulating element; or, at least one of the adhesives bonds one conductive material layer, the isolation region adjacent to the conductive material layer, and the insulating element.

4. The photovoltaic module according to claim 1, characterized in that, The electrode includes a fine grid electrode, and at least one of the adhesives spans at least two of the fine grid electrodes; And / or, at least one of the adhesives bonds the interconnect to the fine gate electrode; And / or, at least one of the adhesives bonds the interconnect to the passivation layer on the surface of the battery cell; And / or, multiple adhesives are distributed in a dotted, discrete manner along the extension direction of the interconnect.

5. The photovoltaic module according to claim 1, characterized in that, The interconnect includes two connecting segments that connect two adjacent battery cells respectively, and at least one of the connecting segments has a continuous adhesive adhered to one side.

6. The photovoltaic module according to claim 1, characterized in that, The adhesive has an uneven surface at the edge away from the interconnect.

7. The photovoltaic module according to claim 6, characterized in that, One side of the battery cell has alternating first and second fine grid electrodes. The interconnect is connected to the first fine grid electrode through the conductive material layer, and an insulating element is provided between the interconnect and the second fine grid electrode. The adhesive protrudes from the conductive material layer to form a protrusion, and is recessed from the insulating component to form a recess.

8. The photovoltaic module according to claim 1, characterized in that, The interconnecting element is either a flat solder strip or a round wire solder strip; Part of the adhesive is located below the interconnect.

9. The photovoltaic module according to claim 1, characterized in that, The adhesive is adhered to at least one end of the interconnect.

10. The photovoltaic module according to claim 9, characterized in that, At least one end of the interconnect has the adhesive surrounding the end of the interconnect on three sides; or, at least one end of the interconnect extends beyond the adhesive adhered to that end, with a portion of the adhesive located below the end region of the interconnect.

11. The photovoltaic module according to any one of claims 1-10, characterized in that, Along the extension direction of the interconnect, the length of one of the adhesives is a, and the length of the conductive material layer bonded by the adhesive is b; a≥b, or, 0.8b≤a≤4.3b, or, 1.15b≤a≤3.3b.

12. The photovoltaic module according to any one of claims 1-10, characterized in that, One of the interconnects has an X portion located on one of the battery cells; the length of the adhesive corresponding to one side of the X portion is m, and the length of the corresponding conductive material layer is n, where 1.5n≤m≤4n.

13. The photovoltaic module according to any one of claims 1-10, characterized in that, Along the extension direction of the interconnect, the length of the adhesive attached to a portion of the interconnect located on a battery cell is less than the length of that portion of the interconnect, and the length difference is between 2mm and 18mm.

14. The photovoltaic module according to any one of claims 1-10, characterized in that, At the same location on the interconnect, the widths of the adhesives adhering to both sides of the interconnect are not equal.

15. The photovoltaic module according to any one of claims 1-10, characterized in that, The width of the adhesive adhering to one side of the interconnect is less than or equal to 1.8 times the width of the interconnect.

16. The photovoltaic module according to any one of claims 1-10, characterized in that, Along the first direction, the adhesive protrudes beyond the size of the conductive material layer: the size of the conductive material layer is 1:(1.6-12).

17. The photovoltaic module according to any one of claims 1-10, characterized in that, Along the thickness direction of the battery cell, the top of the adhesive is not lower than one-quarter of the height of the interconnect.

18. The photovoltaic module according to any one of claims 1-10, characterized in that, The adhesive comprises rosin.

19. The photovoltaic module according to any one of claims 1-10, characterized in that, The interconnect has a position A and a position B, where position A is the end of the interconnect and position B is the area outside the end of the interconnect. At location A, the adhesive bonds at least the interconnect and the electrode; and / or, at location B, the adhesive bonds the interconnect, the conductive material layer, and the electrode.

20. The photovoltaic module according to any one of claims 1-10, characterized in that, The two ends of the interconnect connecting adjacent battery cells have at least one different shape or size of the adhesive; And / or, the interconnect connecting adjacent battery cells includes a first segment located on the preceding battery cell and a second segment located on the following battery cell, wherein the shape of the adhesive on the side of the first segment of the interconnect is the same as the shape of the adhesive on the side of the second segment.

21. The photovoltaic module according to any one of claims 1-10, characterized in that, The solar cell is a back-contact solar cell without a main grid; The electrode includes a first fine grid electrode and a second fine grid electrode. On one side of the battery cell, the first fine grid electrode and the second fine grid electrode extend along the first direction and are alternately distributed along the second direction. The interconnect is connected to the connection portion on the first fine grid electrode through the conductive material layer. The interconnect is isolated from the second fine grid electrode below it by an insulating member or the second fine grid electrode below the interconnect is interrupted.

22. A photovoltaic system, characterized in that, Includes the photovoltaic module as described in any one of claims 1 to 21.

Images