Back contact cell, back contact laminated cell and photovoltaic module

Abstract

The invention provides a back contact cell, a back contact laminated cell and a photovoltaic module. The back contact battery comprises a body, a grid line extending along a first direction, a bonding pad, a connecting line, first insulation paste and second insulation paste. The grid lines are located on the backlight face of the body and are arranged at intervals in the second direction, the bonding pads are connected with the grid lines and are arranged at intervals in the second direction, and the two ends, in the second direction, of the connecting lines are connected with the adjacent bonding pads respectively. The grid lines comprise first grid lines arranged in the first direction with the connecting lines, and first gaps are reserved between the ends of the first grid lines and the connecting lines in the first direction. The first insulation paste and the second insulation paste are arranged along the first direction, the first insulation paste covers the end part of the first grid line, the second insulation paste covers the connecting line, and the second insulation paste can support the welding strip, so that the bending deformation degree of the welding strip is reduced, the risks of disconnection between the welding strip and the bonding pad, damage to the welding strip and the like are reduced, and the performance of the back contact battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic cells, and in particular to a back-contact cell, a back-contact tandem cell, and a photovoltaic module. Background Art

[0002] The backlight surface of the back-contact cell includes a plurality of fine grids and a plurality of pads. The fine grids with opposite polarities are arranged alternately at intervals, and the pads are connected to the fine grids. The pads are used for welding and fixing with welding tapes to collect the current of the back-contact cell.

[0003] The backlight surface of the back-contact cell further includes connecting lines. Along the extending direction of the welding tape, the connecting lines are used for connecting adjacent pads. The fine grid with the opposite polarity to the connecting line is denoted as the first fine grid, and there is a gap between the first fine grid and the connecting line, so that the first fine grid is insulated from the connecting line.

[0004] The welding tape is partially suspended at the gap between the first fine grid and the connecting line. During processes such as welding, installation, transportation, and use, there are risks such as the welding tape being bent due to uneven force, the connection between the welding tape and the pad being disconnected, and the welding tape being damaged.

[0005] Therefore, how to improve the force uniformity of the welding tape is an important problem to be solved in this field. Summary of the Invention

[0006] In view of this, the present application provides a back-contact cell, a back-contact tandem cell, and a photovoltaic module, which can support the welding tape to improve the force uniformity of the welding tape.

[0007] The first aspect of the present application provides a back-contact cell, which includes a body, grid lines extending along a first direction, pads, connecting lines, a first insulating adhesive, and a second insulating adhesive. The grid lines are located on the backlight surface of the body, and a plurality of grid lines are arranged at intervals along a second direction. The pads are connected to the grid lines, and a plurality of pads are arranged at intervals along the second direction. In the second direction, the two ends of the connecting lines are respectively connected to adjacent pads. The grid lines include first grid lines, and the first grid lines and the connecting lines are arranged in the first direction. There is a first gap between the end of the first grid line and the connecting line in the first direction. The first insulating adhesive and the second insulating adhesive are arranged in the first direction. The first insulating adhesive covers the end of the first grid line, and the second insulating adhesive covers the connecting lines. In the second direction, the width of the second insulating adhesive is smaller than the width of the first insulating adhesive.

[0008] In the present application, adjacent pads with the same polarity are electrically connected through connecting lines, reducing the risk that the current of the grid lines cannot be collected after the connection between the pads and the welding tapes fails, and thus improving the output power of the back-contact cell.

[0009] The first insulating adhesive covers the grid line adjacent to the connecting line and with the opposite polarity to the connecting line, reducing the risk of short circuit of the back-contact cell caused by the offset of the welding tape and improving the performance of the back-contact cell.

[0010] The connection line is covered with a second insulating adhesive, which can support the welding tape, reduce the degree of bending deformation of the welding tape, thereby reducing the risks such as the disconnection of the connection between the welding tape and the pad and the damage of the welding tape, and improving the performance of the back contact battery.

[0011] In some possible designs, in the first direction, the second insulating adhesive is connected to the first insulating adhesive.

[0012] In some possible designs, the second insulating adhesive includes a main body portion and a connecting portion. The connecting portion includes a first end and a second end. In the first direction, the first end is connected to the main body portion, and the second end is connected to the first insulating adhesive. In the second direction, the width of the first end is smaller than the width of the second end.

[0013] In some possible designs, the connecting portion includes a first side wall and a second side wall that are oppositely arranged in the second direction, and the first side wall and the second side wall are configured as arc surfaces.

[0014] In some possible designs, the first insulating adhesive and the second insulating adhesive are configured as an integral structure.

[0015] In some possible designs, there is a third gap between the second insulating adhesive and the first insulating adhesive in the first direction.

[0016] In some possible designs, the first insulating adhesive includes a first edge and a second edge that are oppositely arranged in the second direction, and the second insulating adhesive includes a third edge and a fourth edge that are oppositely arranged in the second direction. The first edge, the second edge, the third edge, and the fourth edge are parallel, and in the second direction, the distance between the first edge and the third edge is equal to the distance between the second edge and the fourth edge.

[0017] In some possible designs, in the thickness direction of the back contact battery, the thickness of the second insulating adhesive is less than or equal to the thickness of the first insulating adhesive.

[0018] In a second aspect of the present application, a back contact stacked cell is provided. The back contact stacked cell includes a back contact bottom cell and a perovskite top cell. The perovskite top cell is electrically connected to the light-facing surface of the back contact bottom cell, and the back contact bottom cell is configured as the back contact cell described in any one of the above.

[0019] In a third aspect of the present application, a photovoltaic module is provided. The photovoltaic module includes a cover plate, an encapsulation layer, and a cell layer. The cell layer includes a plurality of the back contact cells described in any one of the above, and / or the cell layer includes a plurality of the above-described back contact stacked cells.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of a partial structure of the back-contact battery provided by the present application in some embodiments; Figure 2 It is Figure 1 an enlarged view of part A in in some embodiments; Figure 3 It is Figure 1 an enlarged view of part A in in some other embodiments; Figure 4 It is Figure 3 an enlarged view of part B in in some embodiments; Figure 5 It is Figure 3 an enlarged view of part B in in some other embodiments; Figure 6 It is Figure 3 an enlarged view of part B in in some other embodiments; Figure 7 It is a schematic diagram of the structure of the first insulating glue and the second insulating glue in some embodiments; Figure 8 It is Figure 7 a schematic diagram of the structure of the second insulating glue in ; Figure 9 It is a schematic diagram of the structure of the first insulating glue and the second insulating glue in some other embodiments; Figure 10 It is Figure 3 an enlarged view of part B in in some other embodiments; Figure 11 It is Figure 10 a schematic diagram of the structure of the first insulating glue and the second insulating glue in in some other embodiments; Figure 12 It is a schematic diagram of the structure of the first insulating glue and the second insulating glue in some other embodiments; Figure 13 It is a schematic diagram of the structure of the first insulating glue and the second insulating glue in some other embodiments; Figure 14 It is a schematic diagram of the structure of the back-contact battery and the solder tape in some embodiments; Figure 15 It is a schematic diagram of the structure of the back-contact battery and the solder tape in some other embodiments; Figure 16Schematic diagram of the stacked structure of the back-contact stacked cell provided by the present application in some embodiments; Figure 17 Schematic diagram of the structure of the photovoltaic module provided by the present application in some embodiments.

[0023] Reference numerals: 10 - Cover plate; 101 - First cover plate; 102 - Second cover plate; 20 - Encapsulation layer; 201 - First adhesive film; 202 - Second adhesive film; 30 - Cell layer; 301 - Back-contact cell; 302 - Perovskite top cell; 303 - Back-contact stacked cell; 40 - Welding ribbon; 1 - Body; 2 - Grid line; 21 - First grid line; 22 - Second grid line; 3 - Pad; 31 - First pad; 32 - Second pad; 4 - Connecting wire; 5 - First insulating glue; 51 - First edge; 52 - Second edge; 6 - Second insulating glue; 61 - Body part; 6,11 - Third edge; 6,12 - Fourth edge; 62 - Connecting part; 621 - First end; 622 - Second end; 623 - First side wall; 624 - Second side wall; 7 - First gap; 8 - Second gap; 9 - Third gap; X - First direction; Y - Second direction; Z - Third direction. Detailed implementation manners

[0024] For a better understanding of the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0025] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0026] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0027] It should be understood that the term " / and / " used herein is only a description of the associated relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0028] The first aspect of the embodiments of the present application provides a back contact battery. In some embodiments, the type of the back contact battery cell can be one of an Interdigitated Back Contact (IBC) battery, a Heterojunction Back Contact (HBC) battery, and a Tunnel Oxide Back Contact (TBC) battery.

[0029] For an IBC battery, along its thickness direction, the IBC battery sequentially includes a silicon nitride back layer, an N+ front surface field, an N-type substrate silicon layer, a P+ emitter, an N+ back field, an alumina passivation layer, a silicon nitride antireflection layer, and a metal silver electrode.

[0030] The IBC battery uses ion implantation technology to obtain P regions and N regions with good uniformity and precisely controllable junction depths. There are no grid lines blocking on the front side of the battery, which can eliminate the shading current loss of the metal electrodes and maximize the utilization of incident photons. The short-circuit current can be increased by about 7% compared with conventional solar cells; due to the back contact structure, there is no need to consider the problem of grid line blockage, and the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor; the surface passivation and surface light trapping structure can be optimized, and a lower front surface recombination rate and surface reflection can be obtained.

[0031] For an HBC battery, the HBC battery combines the advantages of an IBC battery and a heterojunction battery well. Its front surface passivation layer uses hydrogenated amorphous silicon, and N-type and P-type amorphous silicon thin films are respectively deposited on the back to form a heterojunction.

[0032] The HBC battery makes full use of the excellent surface passivation performance of amorphous silicon. The heterojunction structure formed on the back has a good passivation effect, and can simultaneously achieve a higher short-circuit current and open-circuit voltage, thereby improving the photoelectric conversion efficiency.

[0033] For a TBC battery, the TBC battery combines the advantages of the tunneling oxide layer technology of Topcon and the back-arranged electrodes of IBC. The passivation effect and open-circuit voltage are significantly improved, and it can be economical while achieving a higher battery conversion efficiency.

[0034] The complete production process of the TBC battery mainly includes depositing a tunneling oxide layer and P+ polysilicon, depositing a passivation film, printing electrodes on the back of the silicon wafer, etc. The TBC battery needs to add related processes for the back electrodes such as masking, laser grooving, PN region preparation, and etching on the basis of the TOPCon production process. The masking is mainly completed by APCVD or PECVD, the preparation of the PN region is mainly completed by PECVD, the etching mainly uses traditional wet equipment, and the grooving process needs to be completed by a laser device.

[0035] The embodiments of the present application do not make special limitations on the specific types of back-contact batteries.

[0036] The back-contact battery can be configured as a main-gridless battery or a main-grid battery. The embodiments of the present application do not make special limitations on the number of main grids of the back-contact battery.

[0037] When the back-contact battery is configured as a main-gridless battery, Figure 1 is a schematic diagram of a partial structure of the back-contact battery in some embodiments. As Figure 1 shown, the back-contact battery includes a body 1, and the body 1 has a light-facing surface and a backlight surface that are oppositely arranged along its own thickness direction. Among them, the light-facing surface refers to the side of the body 1 facing the sun when the back-contact battery is in a working state, and the backlight surface refers to the side of the body 1 facing away from the sun when the back-contact battery is in a working state. It can also be understood that the light-facing surface is the upper surface of the body 1, and the backlight surface is the lower surface of the body 1.

[0038] As Figure 1 shown, grid lines 2 extending along the first direction X are arranged on the backlight surface of the body 1, and a plurality of grid lines 2 are arranged along the second direction Y. Denote the thickness direction of the back-contact battery as the third direction Z, then both the first direction X and the second direction Y are perpendicular to the third direction Z. Exemplarily, one of the first direction X and the second direction Y is the length direction of the back-contact battery, and the other is the width direction of the back-contact battery.

[0039] As Figure 1 shown, pads 3 are also arranged on the backlight surface of the body 1. The pads 3 are in contact with the grid lines 2, that is, the pads 3 are electrically connected to the grid lines 2. The pads 3 are used for welding and fixing with solder tapes 40, so that a plurality of back-contact batteries are electrically connected.

[0040] Figure 2 is Figure 1 an enlarged view of part A in Figure 2 . As

[0041] shown, the grid lines 2 include a first grid line 21 and a second grid line 22 with opposite polarities. The first grid line 21 and the second grid line 22 are arranged at intervals and alternately along the second direction Y. One of the first grid line 21 and the second grid line 22 is configured as the positive grid line of the back-contact battery, and the other is configured as the negative grid line of the back-contact battery. Figure 2 shown, the pads 3 include a first pad 31 and a second pad 32. A plurality of first pads 31 are arranged at intervals along the second direction Y. The first pads 31 are electrically connected to the first grid line 21, and the second pads 32 are electrically connected to the second grid line 22. A plurality of second pads 32 are arranged at intervals along the second direction Y. The first pads 31 and the second pads 32 are arranged in the first direction X, and the first pads 31 and the second pads 32 are not aligned in the first direction X.

[0042] In some embodiments, with reference to Figure 2 the structure shown, the pads 3 adjacent in the second direction Y are electrically connected through a solder strip 40.

[0043] Figure 3 is Figure 1 an enlarged view of part A in Figure 3 in some other embodiments. In some other embodiments, as Figure 3 shown, the back contact battery further includes a connecting wire 4. In the second direction Y, both ends of the connecting wire 4 are respectively connected to adjacent pads 3. That is, the pads 3 adjacent in the second direction Y are electrically connected through the connecting wire 4.

[0044] In this embodiment, the pads 3 adjacent in the second direction Y are electrically connected through the connecting wire 4. When the electrical connection between a certain pad 3 and the solder strip 40 fails, the current on the gate line 2 connected to this pad 3 can be transmitted through the connecting wire 4 to the adjacent pad 3, so as to realize the collection of the current on the gate line 2 by the solder strip 40, reduce the risk that the current on the gate line 2 connected to this pad 3 cannot be collected, and further improve the output power of the back contact battery.

[0045] The connecting wire 4 can be connected to two adjacent first pads 31, or can be connected to two adjacent second pads 32. The embodiments of the present application do not make special limitations on the position and quantity of the connecting wire 4. For the convenience of description, hereinafter, the example where both ends of the connecting wire 4 are respectively connected to adjacent second pads 32 is taken.

[0046] Figure 4 is Figure 3 an enlarged view of part B in some embodiments. As Figure 4 shown, both ends of the connecting wire 4 are respectively connected to adjacent second pads 32, and the second pad 32 is connected to the second gate line 22. That is, the first gate line 21 and the connecting wire 4 have the same polarity, and there is a first gate line 21 with a polarity opposite to that of the second gate line 22 between two adjacent second gate lines 22.

[0047] As Figure 4 shown, the first gate line 21 and the connecting wire 4 are arranged in the first direction X, and there is a first gap 7 between the end of the first gate line 21 and the connecting wire 4 in the first direction X, so that the first gate line 21 and the connecting wire 4 are insulated, reducing the risk of short - circuit of the back contact battery caused by the contact between the first gate line 21 and the connecting wire 4.

[0048] Figure 5 is Figure 3 an enlarged view of part B in some other embodiments. As Figure 5As shown, the back-contact battery further includes a first insulating adhesive 5 extending along a first direction X. The first insulating adhesive 5 and the connection line 4 are arranged along the first direction X. The first insulating adhesive 5 is used to cover the end of the first gate line 21 facing the connection line 4, thereby reducing the risk of short circuit of the back-contact battery caused by the electrical connection between the solder strip 40 and the first gate line 21 after the solder strip 40 is offset.

[0049] In the first direction X, the first insulating adhesive 5 can be located on one side of the connection line 4 or on both sides of the connection line 4. Figure 5 An example shows that the first insulating adhesives 5 are provided on both sides of the connection line 4. A second gap 8 is left between two adjacent first insulating adhesives 5 in the first direction X. A part of the connection line 4 is located in the second gap 8, that is, the connection line 4 passes through the second gap 8 along a second direction Y and is connected to two adjacent second pads 32.

[0050] A second gap 8 is left between two adjacent first insulating adhesives 5. A part of the solder strip 40 is suspended at the second gap 8. During subsequent processing, transportation, installation, and use, there is a risk that the solder strip 40 is unevenly stressed and bends into the second gap 8, and there are risks such as the disconnection of the connection between the solder strip 40 and the pad 3 and the damage of the solder strip 40.

[0051] In view of this, the back-contact battery provided by the embodiment of the present application further includes a second insulating adhesive 6 located in the second gap 8.

[0052] Figure 6 For Figure 3 an enlarged view of part B in some other embodiments. As Figure 6 shown, the back-contact battery further includes a second insulating adhesive 6. The second insulating adhesive 6 and the first insulating adhesive 5 are arranged along the first direction X. At least part of the structure of the second insulating adhesive 6 is located in the second gap 8. In a third direction Z, the second insulating adhesive 6 covers the connection line 4.

[0053] In this embodiment, the second insulating adhesive 6 is covered above the connection line 4. When the solder strip 40 bends into the second gap 8, the second insulating adhesive 6 can support the solder strip 40, thereby reducing the degree of bending deformation of the solder strip 40, and further reducing the risks such as the disconnection of the connection between the solder strip 40 and the pad 3 and the damage of the solder strip 40.

[0054] As Figure 6As shown, in the second direction Y, the width of the second insulating adhesive 6 is smaller than that of the first insulating adhesive 5, thereby reducing the risk of the second insulating adhesive 6 coming into contact with the adjacent second pad 32, reducing the risk of residues remaining on the second pad 32 due to the curing of the second insulating adhesive 6, and reducing the risk of position deviation during the curing of the solder paste resulting in poor soldering of the solder strip 40, that is, reducing the risk of poor soldering between the solder strip 40 and the second pad 32 caused by the contact between the second insulating adhesive 6 and the adjacent second pad 32, so as to improve the connection reliability between the solder strip 40 and the pad 3, and further improve the performance of the back-contact battery.

[0055] In some embodiments, as Figure 6 shown, in the first direction X, the second insulating adhesive 6 is connected to the first insulating adhesive 5, so as to facilitate increasing the supporting effect of the second insulating adhesive 6 on the solder strip 40 and reducing the risk of the solder strip 40 tilting due to a part of the solder strip 40 in the first direction X coming into contact with the second insulating adhesive 6 while the other part is suspended.

[0056] Figure 7 is a schematic structural diagram of the first insulating adhesive 5 and the second insulating adhesive 6 in some embodiments, Figure 8 is Figure 7 a schematic structural diagram of the second insulating adhesive 6 in Figure 7 and Figure 8 are referred to. The second insulating adhesive 6 includes a body portion 61 and a connecting portion 62. The connecting portion 62 includes a first end 621 and a second end 622. In the first direction X, the first end 621 is connected to the body portion 61, and the second end 622 is connected to the first insulating adhesive 5.

[0057] As Figure 8 shown, in the second direction Y, the width of the first end 621 is smaller than that of the second end 622, that is, as Figure 8 shown, the width of the connecting end is a gradually changing value. That is, along the first direction X, in the direction from the first insulating adhesive 5 to the second insulating adhesive 6, the width of the connecting end gradually decreases.

[0058] In this embodiment, the width of the side of the connecting portion 62 close to the first insulating adhesive 5 is greater than the width of the side close to the body portion 61, thereby increasing the width dimension of the connection position between the second insulating adhesive 6 and the first insulating adhesive 5, and thus improving the connection reliability between the first insulating adhesive 5 and the second insulating adhesive 6.

[0059] As Figure 8 shown, the connecting portion 62 includes a first side wall 623 and a second side wall 624 that are oppositely arranged in the second direction Y. The first side wall 623 and the second side wall 624 can be configured as straight surfaces or can be configured as arc surfaces.

[0060] In this embodiment, the first side wall 623 and the second side wall 624 are configured as arc surfaces, such that the first insulating adhesive 5 and the second insulating adhesive 6 are connected through an arc transition. While increasing the connection area between the first insulating adhesive 5 and the second insulating adhesive 6, the projected area of the second insulating adhesive 6 in the third direction Z can be reduced, thereby reducing the material cost of the second insulating adhesive 6.

[0061] When the second insulating adhesive 6 is connected to the first insulating adhesive 5, the first insulating adhesive 5 and the second insulating adhesive 6 can be configured as an integral structure or a split structure.

[0062] Figure 7 An example shows that the first insulating adhesive 5 and the second insulating adhesive 6 are configured as a split structure, that is, the first insulating adhesive 5 and the second insulating adhesive 6 are formed in two steps to simplify the structure of the printing screen for the adhesive.

[0063] Figure 9 FIG. is a schematic structural diagram of the first insulating adhesive 5 and the second insulating adhesive 6 in some other embodiments. As Figure 9 shown, the first insulating adhesive 5 and the second insulating adhesive 6 are configured as an integral structure, that is, the first insulating adhesive 5 and the second insulating adhesive 6 are integrally formed to simplify the processing of the first insulating adhesive 5 and the second insulating adhesive 6.

[0064] Figure 6 、 Figure 7 and Figure 9 An example shows the connection between the first insulating adhesive 5 and the second insulating adhesive 6.

[0065] In some other embodiments, the first insulating adhesive 5 and the second insulating adhesive 6 are not connected. Figure 10 FIG. is Figure 3 an enlarged view of part B in still some other embodiments, Figure 11 FIG. is Figure 10 a schematic structural diagram of the first insulating adhesive 5 and the second insulating adhesive 6 in still some other embodiments. Referring to Figure 10 and Figure 11 simultaneously, a third gap 9 is left between the second insulating adhesive 6 and the first insulating adhesive 5 in the first direction X.

[0066] In this embodiment, the first insulating adhesive 5 and the second insulating adhesive 6 are not connected, reducing the size of the second insulating adhesive 6 in the first direction X, which is beneficial to reducing the projected area of the second insulating adhesive 6 in the third direction Z, thereby reducing the material cost of the second insulating adhesive 6.

[0067] Taking the connection between the first insulating adhesive 5 and the second insulating adhesive 6 as an example.

[0068] Figure 12 FIG. is a schematic structural diagram of the first insulating adhesive 5 and the second insulating adhesive 6 in still some other embodiments. As Figure 12As shown, the first insulating adhesive 5 includes a first edge 51 and a second edge 52 that are oppositely arranged along the second direction Y. The second insulating adhesive 6 includes a third edge 611 and a fourth edge 612 that are oppositely arranged along the second direction Y. The first edge 51 and the third edge 611 are on the same side, the second edge 52 and the fourth edge 612 are on the same side, and the first edge 51, the second edge 52, the third edge 611, and the fourth edge 612 are parallel.

[0069] In some embodiments, as Figure 12 shown, in the second direction Y, the distance between the first edge 51 and the third edge 611 is less than the distance between the second edge 52 and the fourth edge 612. That is, in the second direction Y, the second insulating adhesive 6 is located on the side close to the first edge 51.

[0070] Figure 13 FIG. is a schematic structural diagram of the first insulating adhesive 5 and the second insulating adhesive 6 in still other embodiments. In other embodiments, as Figure 13 shown, in the second direction Y, the distance between the first edge 51 and the third edge 611 is equal to the distance between the second edge 52 and the fourth edge 612. That is, the second insulating adhesive 6 is centrally disposed between two adjacent first insulating adhesives 5 in the second direction Y.

[0071] In this embodiment, the second insulating adhesive 6 is centrally disposed in the second direction Y, so that the distances between the second insulating adhesive 6 and the adjacent two second pads 32 are equal or approximately equal, reducing the risk that the connection between the second pad 32 on one side and the solder strip 40 fails due to a relatively small distance between the second insulating adhesive 6 and the second pad 32 on one side.

[0072] Figure 14 FIG. is a schematic structural diagram of the back contact battery and the solder strip 40 in some embodiments. As Figure 14 shown, in the third direction Z, the thickness of the second insulating adhesive 6 is equal to the thickness of the first insulating adhesive 5.

[0073] Figure 15 FIG. is a schematic structural diagram of the back contact battery and the solder strip 40 in other embodiments. As Figure 15 shown, in the third direction Z, the thickness of the second insulating adhesive 6 is less than the thickness of the first insulating adhesive 5.

[0074] In this embodiment, the second insulating adhesive 6 is lower than the first insulating adhesive 5. When the solder strip 40 is bent and deformed in the direction close to the second insulating adhesive 6, the second insulating adhesive 6 can still contact and support the solder strip 40, thereby reducing the deformation amount of the solder strip 40 to improve the connection stability between the solder strip 40 and the pad 3. The thickness of the second insulating adhesive 6 is less than the thickness of the first insulating adhesive 5, reducing the size of the second insulating adhesive 6 in the third direction Z, which is beneficial to reducing the material cost of the second insulating adhesive 6.

[0075] In this embodiment, the thickness of the second insulating adhesive 6 can be equal to or less than the thickness of the first insulating adhesive 5, that is, the second insulating adhesive 6 is not higher than the first insulating adhesive 5, reducing the risk that the second insulating adhesive 6 jacks up the solder strip 40 and causes poor soldering between the solder strip 40 and the pad 3. Furthermore, the connection stability between the solder strip 40 and the pad 3 is improved, which is beneficial to improving the performance of the back-contact battery.

[0076] In the second aspect of the embodiments of the present application, a back-contact stacked battery is provided. Figure 16 As shown in the schematic diagram of the stacked structure of the back-contact stacked battery provided in some embodiments of the present application, Figure 16 as shown, the back-contact stacked battery 303 includes a perovskite top cell 302 and a back-contact bottom cell 301 stacked along the third direction Z. The perovskite top cell 302 is electrically connected to the light-facing surface of the back-contact bottom cell 301, and the back-contact bottom cell 301 is configured as the above-mentioned back-contact battery.

[0077] The perovskite top cell 302 is a thin-film solar cell with a perovskite material as the photoactive layer. The structure of the perovskite top cell 302 mainly consists of the following key parts: a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode. These components work together to enable the perovskite top cell 302 to effectively absorb sunlight and convert it into electrical energy. The perovskite material in the perovskite light-absorbing layer has excellent light absorption performance, can absorb a wider spectral range, and effectively convert short-wavelength spectra, enabling the perovskite top cell 302 to have a high photoelectric conversion efficiency.

[0078] In the third aspect of the embodiments of the present application, a photovoltaic module is provided. Figure 17 As shown in the schematic diagram of the structure of the photovoltaic module provided in some embodiments of the present application, Figure 17 as shown, the photovoltaic module includes a cover plate 10, a packaging layer 20, and a cell layer 30.

[0079] The cover plate 10 includes a first cover plate 101 and a second cover plate 102 arranged along the third direction Z. The packaging layer 20 and the cell layer 30 are located between the first cover plate 101 and the second cover plate 102, and a part of the packaging layer 20 is located between the cell layer 30 and the first cover plate 101, and another part of the packaging layer 20 is located between the cell layer 30 and the second cover plate 102 to achieve the packaging and fixation of the cover plate 10 and the cell layer 30.

[0080] At least one of the first cover plate 101 and the second cover plate 102 is made of a light-transmissive material, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0081] The material of the first cover plate 101 can be one of rigid materials such as tempered glass, PET (Polyethylene Terephthalate), PC (Polycarbonate), etc. Or, the material of the first cover plate 101 can be one of flexible materials such as PVF (Polyvinyl Fluoride), ETFE (Ethylene-Tetra-Fluoro-Ethylene), PVDF (Polyvinylidene Fluoride), etc. These materials mentioned above all have a high light transmittance, which can ensure that more light irradiates on the battery layer, thereby increasing the light absorption of the photovoltaic module and improving the photoelectric conversion efficiency of the photovoltaic module.

[0082] The material of the second cover plate 102 can be one of rigid materials such as tempered glass, PET (Polyethylene Terephthalate), PC (Polycarbonate), etc. Or, the material of the second cover plate 102 can be one of flexible materials such as PVF (Polyvinyl Fluoride), ETFE (Ethylene-Tetra-Fluoro-Ethylene), PVDF (Polyvinylidene Fluoride), etc.

[0083] The materials of the first cover plate 101 and the second cover plate 102 can be the same or different.

[0084] As Figure 17 shown, the encapsulation layer 20 includes a first adhesive film 201 and a second adhesive film 202. In the third direction Z, a part of the structure of the first adhesive film 201 is located between the battery layer 30 and the first cover plate 101, and a part of the structure of the second adhesive film 202 is located between the battery layer and the second cover plate 102.

[0085] The material of the first adhesive film 201 is one of polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), PVB (Polyvinyl Butyral), etc. The above several materials have a high light transmittance, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0086] The material of the second encapsulant film 202 is one of polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral).

[0087] The materials of the first encapsulant film 201 and the second encapsulant film 202 can be the same or different.

[0088] The cell layer 30 includes multiple cell strings connected in series or in parallel. Each cell string is formed by connecting multiple solar cells (including but not limited to monocrystalline silicon solar cells and polycrystalline silicon solar cells) in series, and adjacent two solar cells are connected by a welding ribbon.

[0089] The solar cell can be the above-mentioned back-contact solar cell or the above-mentioned back-contact stacked solar cell 303.

[0090] The cell layer 30 can only include the above-mentioned back-contact solar cells, or only include the above-mentioned back-contact stacked solar cells 303, or can also include both the above-mentioned back-contact solar cells and the above-mentioned back-contact stacked solar cells 303. The embodiments of the present application do not make special limitations on the number, type, series-parallel connection mode, etc. of the solar cells included in the cell layer 30.

[0091] In the embodiments of the present application, adjacent two pads with the same polarity are electrically connected through a connecting wire, reducing the risk that the current of the grid line cannot be collected after the connection between the pad and the welding ribbon fails, and thus improving the output power of the back-contact solar cell and the photovoltaic module having the back-contact solar cell.

[0092] A first insulating glue is covered on the grid line adjacent to the connecting wire and having the opposite polarity to the connecting wire, reducing the risk of short circuit of the back-contact solar cell caused by the offset of the welding ribbon, and improving the performance of the back-contact solar cell and the photovoltaic module having the back-contact solar cell.

[0093] A second insulating glue is covered on the connecting wire. The second insulating glue can support the welding ribbon, reducing the degree of bending deformation of the welding ribbon, and thus reducing the risks such as disconnection of the connection between the welding ribbon and the pad and damage of the welding ribbon, and improving the performance of the back-contact solar cell and the photovoltaic module having the back-contact solar cell.

[0094] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A back-contact battery, characterized in that, The back-contact battery includes: A body (1); Grid lines (2) extending along a first direction (X), the grid lines (2) being located on the backlight surface of the body (1), and a plurality of the grid lines (2) being arranged at intervals along a second direction (Y); Bonding pads (3), the bonding pads (3) being connected to the grid lines (2), and a plurality of the bonding pads (3) being arranged at intervals along the second direction (Y); Connection lines (4), in the second direction (Y), two ends of the connection line (4) being respectively connected to adjacent bonding pads (3); The grid line (2) includes a first grid line (21), the first grid line (21) and the connection line (4) being arranged in the first direction (X), and an end of the first grid line (21) leaving a first gap (7) from the connection line (4) in the first direction (X); A first insulating adhesive (5) and a second insulating adhesive (6) arranged in the first direction (X), the first insulating adhesive (5) covering the end of the first grid line (21), and the second insulating adhesive (6) covering the connection line (4); In the second direction (Y), the width of the second insulating adhesive (6) is smaller than the width of the first insulating adhesive (5).

2. The back-contact battery according to claim 1, characterized in that, In the first direction (X), the second insulating adhesive (6) is connected to the first insulating adhesive (5).

3. The back contact battery according to claim 2, characterized in that, The second insulating adhesive (6) includes a body portion (61) and a connecting portion (62); The connecting portion (62) includes a first end (621) and a second end (622), in the first direction (X), the first end (621) being connected to the body portion (61), and the second end (622) being connected to the first insulating adhesive (5); In the second direction (Y), the width of the first end (621) is smaller than the width of the second end (622).

4. The back-contact battery according to claim 3, characterized in that, The connecting portion (62) includes a first side wall (623) and a second side wall (624) oppositely arranged along the second direction (Y), and the first side wall (623) and the second side wall (624) are configured as arc surfaces.

5. The back-contact battery according to claim 2, characterized in that, The first insulating adhesive (5) and the second insulating adhesive (6) are configured as an integral structure.

6. The back-contact battery according to claim 1, characterized in that, The second insulating adhesive (6) leaves a third gap (9) from the first insulating adhesive (5) in the first direction (X).

7. The back-contact battery according to any one of claims 1 to 6, characterized in that, The first insulating adhesive (5) includes a first edge (51) and a second edge (52) oppositely arranged along the second direction (Y), and the second insulating adhesive (6) includes a third edge (611) and a fourth edge (612) oppositely arranged along the second direction (Y); The first edge (51), the second edge (52), the third edge (611), and the fourth edge (612) are parallel; In the second direction (Y), the distance between the first edge (51) and the third edge (611) is equal to the distance between the second edge (52) and the fourth edge (612).

8. The back-contact battery according to any one of claims 1 to 6, characterized in that, In the thickness direction of the back-contact battery, the thickness of the second insulating adhesive (6) is less than or equal to the thickness of the first insulating adhesive (5).

9. A back-contact stacked cell, characterized in that, The back-contact stacked battery (303) includes: Back-contact bottom cell (301), the back-contact bottom cell (301) being configured as the back-contact cell according to any one of claims 1 to 8; Perovskite top cell (302), the perovskite top cell (302) being electrically connected to the light-facing surface of the back-contact bottom cell (301).

10. A photovoltaic module, characterized in that, The photovoltaic module includes a cover plate (10), an encapsulation layer (20), and a cell layer (30); The cell layer (30) includes a plurality of back-contact cells according to any one of claims 1 to 8, and / or the cell layer (30) includes a plurality of back-contact stacked cells (303) according to claim 9.

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