A back contact cell, back contact laminate cell and photovoltaic module

Abstract

The application provides a back contact battery, a back contact laminated battery and a photovoltaic module. The back contact battery comprises a body, a grid line extending in a first direction, a pad, a connecting line, a first insulating glue and a second insulating glue. The grid line is located on the back light surface of the body, a plurality of grid lines are arranged at intervals in a second direction, the pad is connected with the grid line, a plurality of pads are arranged at intervals in the second direction, and the two ends of the connecting line in the second direction are respectively connected with adjacent pads. The grid line comprises a first grid line arranged in the first direction with the connecting line, and the end of the first grid line is provided with a first gap in the first direction with the connecting line. The first insulating glue and the second insulating glue are arranged in the first direction, the first insulating glue covers the end of the first grid line, the second insulating glue covers the connecting line, the second insulating glue can support the solder strip, the degree of bending deformation of the solder strip is reduced, the risk of disconnection of the solder strip and the pad and damage of the solder strip is reduced, and the performance of the back contact battery is improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell technology, and in particular to a back-contact cell, a back-contact tandem cell, and a photovoltaic module. Background Technology

[0002] The back surface of the back contact battery includes multiple fine grids and multiple pads. The fine grids with opposite polarities are arranged alternately at intervals. The pads are connected to the fine grids and are used to weld and fix them to the solder strip to collect the current of the back contact battery.

[0003] The back surface of the back contact battery also includes connecting lines. Along the extension direction of the solder strip, the connecting lines are used to connect adjacent solder pads. The fine grid with the opposite polarity to the connecting lines is called the first fine grid. A gap is left between the first fine grid and the connecting lines so that the first fine grid is insulated from the connecting lines.

[0004] The solder strip is partially suspended in the gap between the first fine grid and the connecting line. During welding, installation, transportation, and use, there are risks such as uneven stress on the solder strip leading to solder strip bending, breakage of the connection between the solder strip and the pad, and damage to the solder strip.

[0005] Therefore, improving the uniformity of stress on the solder strip is an important problem that needs to be solved in this field. Utility Model Content

[0006] In view of this, this application provides a back-contact cell, a back-contact tandem cell, and a photovoltaic module that can support the solder ribbon to improve the uniformity of stress on the solder ribbon.

[0007] This application provides a back contact battery, comprising 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 back surface of the body, and multiple grid lines are spaced apart along a second direction. The pads are connected to the grid lines, and multiple pads are spaced apart along the second direction. In the second direction, both ends of the connecting lines are connected to adjacent pads. The grid lines include a first grid line, which is arranged with the connecting lines in the first direction. A first gap is left between the end of the first grid line and the connecting lines in the first direction. The first insulating adhesive and the second insulating adhesive are arranged along 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 this application, two adjacent pads of the same polarity are electrically connected by a connecting line, which reduces the risk that the current of the grid line cannot be collected after the connection between the pad and the solder strip fails, thereby improving the output power of the back contact battery.

[0009] The grid line adjacent to the connecting line and with the opposite polarity to the connecting line is covered with a first insulating adhesive, which reduces the risk of short circuit of the back contact battery caused by solder strip misalignment and improves the performance of the back contact battery.

[0010] The connecting line is covered with a second insulating adhesive, which supports the solder ribbon and reduces the degree of bending deformation of the solder ribbon. This reduces the risk of the solder ribbon breaking off from the pad and the solder ribbon being damaged, thus improving the performance of the back contact battery.

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

[0012] In some possible designs, the second insulating adhesive includes a body portion and a connecting portion. The connecting portion includes a first end and a second end. In a first direction, the first end is connected to the body portion, and the second end is connected to the first insulating adhesive. In a 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 sidewall and a second sidewall disposed opposite to each other along a second direction, the first sidewall and the second sidewall being configured as arc surfaces.

[0014] In some possible designs, the first insulating adhesive and the second insulating adhesive are constructed as a single unit.

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

[0016] In some possible designs, the first insulating adhesive includes a first edge and a second edge disposed opposite to each other along a second direction, and the second insulating adhesive includes a third edge and a fourth edge disposed opposite to each other along a 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, the thickness of the second insulating adhesive is less than or equal to the thickness of the first insulating adhesive in the thickness direction of the back contact battery.

[0018] A second aspect of this application provides a back-contact stacked battery, which includes a back-contact bottom battery and a perovskite top battery. The perovskite top battery is electrically connected to the light-facing surface of the back-contact bottom battery, and the back-contact bottom battery is configured as a back-contact battery as described in any of the above claims.

[0019] A third aspect of this application provides a photovoltaic module, which includes a cover plate, an encapsulation layer, and a cell layer. The cell layer includes a plurality of back-contact cells as described in any one of the above claims, and / or, the cell layer includes a plurality of back-contact stacked cells as described above.

[0020] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A partial structural schematic diagram of the back contact battery provided in this application in some embodiments;

[0023] Figure 2 for Figure 1 Enlarged view of part A in some embodiments;

[0024] Figure 3 for Figure 1 Enlarged view of part A in some other embodiments;

[0025] Figure 4 for Figure 3 Enlarged views of part B in some embodiments;

[0026] Figure 5 for Figure 3 Enlarged view of part B in some other embodiments;

[0027] Figure 6 for Figure 3 Enlarged view of part B in some other embodiments;

[0028] Figure 7 This is a schematic diagram of the structure of the first insulating adhesive and the second insulating adhesive in some embodiments;

[0029] Figure 8 for Figure 7 A schematic diagram of the structure of the second insulating adhesive in the process;

[0030] Figure 9 This is a schematic diagram of the structure of the first insulating adhesive and the second insulating adhesive in some other embodiments;

[0031] Figure 10 for Figure 3 Enlarged view of part B in some other embodiments;

[0032] Figure 11 for Figure 10 A schematic diagram of the structure of the first and second insulating adhesives in some other embodiments;

[0033] Figure 12 This is a schematic diagram of the structure of the first insulating adhesive and the second insulating adhesive in some further embodiments;

[0034] Figure 13This is a schematic diagram of the structure of the first insulating adhesive and the second insulating adhesive in some further embodiments;

[0035] Figure 14 This is a schematic diagram of the back contact battery and solder strip in some embodiments;

[0036] Figure 15 This is a schematic diagram of the back contact battery and solder strip in some other embodiments;

[0037] Figure 16 A schematic diagram of the stacked structure of the back contact stacked battery provided in this application in some embodiments;

[0038] Figure 17 The photovoltaic module provided in this application is shown in some embodiments as a structural schematic diagram.

[0039] Figure label:

[0040] 10-Cover plate; 101-First cover plate; 102-Second cover plate;

[0041] 20 - Encapsulation layer; 201 - First adhesive film; 202 - Second adhesive film;

[0042] 30 - Battery layer; 301 - Back contact battery; 302 - Perovskite top battery; 303 - Back contact stacked battery;

[0043] 40 - Welding strip;

[0044] 1-Body; 2-Gate line; 21-First gate line; 22-Second gate line; 3-Pad; 31-First pad; 32-Second pad; 4-Connector line;

[0045] 5-First insulating adhesive; 51-First edge; 52-Second edge;

[0046] 6-Second insulating adhesive; 61-Main body; 611-Third edge; 612-Fourth edge; 62-Connecting part; 621-First end; 622-Second end; 623-First sidewall; 624-Second sidewall;

[0047] 7 - First gap; 8 - Second gap; 9 - Third gap; X - First direction; Y - Second direction; Z - Third direction. Detailed Implementation

[0048] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0049] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0050] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0051] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0052] The first aspect of this application provides a back contact battery. In some embodiments, the back contact battery cells can be one of the following: interdigitated back contact (IBC), heterojunction back contact (HBC), and tunnel oxide back contact (TBC).

[0053] For an IBC cell, along its thickness direction, the IBC cell sequentially includes a silicon nitride inversion layer, an N+ front surface field, an N-type substrate silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride antireflection layer, and a metallic silver electrode.

[0054] IBC cells utilize ion implantation technology to obtain P- and N-regions with good uniformity and precise controllable junction depth. The absence of grid lines on the front of the cell eliminates light-blocking current loss from metal electrodes, maximizing the utilization of incident photons and improving short-circuit current by approximately 7% compared to conventional solar cells. Due to the back-contact structure, grid line shading is not a concern, allowing for a wider grid line ratio, thus reducing series resistance and achieving a high fill factor. Optimized design of surface passivation and light-trapping structures can be achieved, resulting in lower front-surface recombination rates and surface reflections.

[0055] For HBC cells, the advantages of IBC cells and heterojunction cells are well combined. The passivation layer on the front surface is made of hydrogenated amorphous silicon, and N-type and P-type amorphous silicon thin films are deposited on the back to form a heterojunction.

[0056] HBC cells fully utilize the superior surface passivation properties of amorphous silicon. The heterojunction structure formed on the back has a good passivation effect, which can simultaneously achieve higher short-circuit current and open-circuit voltage, thereby improving photoelectric conversion efficiency.

[0057] For TBC batteries, the combination of Topcon's tunneling oxide layer technology and the advantages of IBC back-side electrode arrangement significantly improves passivation effect and open-circuit voltage, achieving higher battery conversion efficiency while being economical.

[0058] The complete production process of TBC cells mainly includes depositing tunneling oxide and P+ polycrystalline silicon, depositing passivation films, and printing electrodes on the back of the silicon wafer. Based on the TOPCon production process, TBC cells require additional back electrode processes such as masking, laser grooving, PN region fabrication, and etching. Masking is mainly done using APCVD or PECVD, PN region fabrication is mainly done using PECVD, etching mainly uses traditional wet processing equipment, and the grooving process requires laser equipment.

[0059] This application does not specifically limit the type of back contact battery in its embodiments.

[0060] The back contact battery can be constructed as a gridless battery or as a battery with a grid. In this application, the number of grids in the back contact battery is not specifically limited.

[0061] When the back-contact battery is constructed as a gridless battery... Figure 1 This is a partial structural diagram of a back-contact battery in some embodiments, such as... Figure 1 As shown, the back contact battery includes a body 1, which has a light-facing surface and a back-light surface arranged opposite to each other along its thickness direction. The light-facing surface is the side of the body 1 facing the sunlight when the back contact battery is in operation, and the back-light surface is the side of the body 1 away from the sunlight when the back contact battery is in operation. The light-facing surface can also be understood as the upper surface of the body 1, and the back-light surface can be understood as the lower surface of the body 1.

[0062] like Figure 1 As shown, the back surface of the body 1 is provided with grid lines 2 extending along the first direction X, and multiple grid lines 2 are arranged along the second direction Y. Let the thickness direction of the back contact battery be denoted as the third direction Z. Then, both the first direction X and the second direction Y are perpendicular to the third direction Z. For example, 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.

[0063] like Figure 1As shown, the back surface of the main body 1 is also provided with a solder pad 3. The solder pad 3 is in contact with the grid line 2, that is, the solder pad 3 is electrically connected to the grid line 2. The solder pad 3 is used to weld and fix to the solder ribbon 40, thereby making multiple back contact batteries electrically connected.

[0064] Figure 2 for Figure 1 Part A in the image is shown as an enlarged view in some embodiments. For example... Figure 2 As shown, the grid line 2 includes 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 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.

[0065] like Figure 2 As shown, pad 3 includes a first pad 31 and a second pad 32. Multiple first pads 31 are arranged at intervals along a second direction Y. The first pads 31 are electrically connected to the first gate line 21, and the second pads 32 are electrically connected to the second gate line 22. Multiple second pads 32 are arranged at intervals along the second direction Y. The first pads 31 and the second pads 32 are arranged in a first direction X, and the first pads 31 and the second pads 32 are not aligned in the first direction X.

[0066] In some embodiments, reference Figure 2 In the structure shown, adjacent pads 3 in the second direction Y are electrically connected by solder strips 40.

[0067] Figure 3 for Figure 1 A magnified view of part A in some other embodiments. In other embodiments, such as Figure 3 As shown, the back contact battery also includes a connecting line 4. In the second direction Y, the two ends of the connecting line 4 are respectively connected to adjacent pads 3. That is, adjacent pads 3 in the second direction Y are electrically connected through the connecting line 4.

[0068] In this embodiment, adjacent pads 3 in the second direction Y are electrically connected by a connecting line 4. When the electrical connection between a pad 3 and the solder ribbon 40 fails, the current on the gate line 2 connected to the pad 3 can be transmitted to the adjacent pad 3 through the connecting line 4, so as to realize the collection of the current on the gate line 2 by the solder ribbon 40, reducing the risk that the current on the gate line 2 connected to the pad 3 cannot be collected, thereby improving the output power of the back contact battery.

[0069] The connecting line 4 can be connected to two adjacent first pads 31 or two adjacent second pads 32. In this embodiment, the position and number of connecting lines 4 are not specifically limited. For ease of description, the following example will be taken where both ends of the connecting line 4 are connected to adjacent second pads 32.

[0070] Figure 4 for Figure 3 Part B in the diagram is an enlarged view in some embodiments. For example... Figure 4 As shown, the two ends of the connecting line 4 are respectively connected to the adjacent second pad 32. The second pad 32 is connected to the second gate line 22. That is, the polarity of the first gate line 21 and the connecting line 4 is the same, and there is a first gate line 21 with the opposite polarity to the second gate line 22 between two adjacent second gate lines 22.

[0071] like Figure 4 As shown, the first grid line 21 and the connecting line 4 are arranged in the first direction X. The end of the first grid line 21 and the connecting line 4 are separated by a first gap 7 in the first direction X, so that the first grid line 21 and the connecting line 4 are insulated, reducing the risk of short circuit of the back contact battery caused by the contact between the first grid line 21 and the connecting line 4.

[0072] Figure 5 for Figure 3 Enlarged views of part B in other embodiments. For example... Figure 5 As shown, the back contact battery also includes a first insulating adhesive 5 extending along the first direction X. The first insulating adhesive 5 and the connecting line 4 are arranged along the first direction X. The first insulating adhesive 5 is used to cover the end of the first grid line 21 facing the connecting line 4, thereby reducing the risk of short circuit of the back contact battery caused by the electrical connection between the solder ribbon 40 and the first grid line 21 after the solder ribbon 40 is offset.

[0073] In the first direction X, the first insulating adhesive 5 can be located on one side of the connecting wire 4 or on both sides of the connecting wire 4. Figure 5 The example shows that both sides of the connecting line 4 are provided with first insulating adhesive 5, and a second gap 8 is left between two adjacent first insulating adhesives 5 in the first direction X. A part of the connecting line 4 is located in the second gap 8, that is, the connecting line 4 passes through the second gap 8 along the second direction Y and is connected to two adjacent second pads 32.

[0074] A second gap 8 is left between two adjacent first insulating adhesives 5. A part of the solder ribbon 40 is suspended in the second gap 8. During subsequent processing, transportation, installation and use, there is a risk that the solder ribbon 40 may be bent into the second gap 8 due to uneven stress, and there is a risk that the solder ribbon 40 may be disconnected from the solder pad 3 and that the solder ribbon 40 may be damaged.

[0075] Therefore, the back contact battery provided in this application embodiment also includes a second insulating adhesive 6 located within the second gap 8.

[0076] Figure 6 for Figure 3 Part B in the diagram is shown as an enlarged view in some other embodiments. For example... Figure 6As shown, the back contact battery also includes a second insulating adhesive 6, which is arranged with the first insulating adhesive 5 along the first direction X. At least a portion of the structure of the second insulating adhesive 6 is located within the second gap 8. In the third direction Z, the second insulating adhesive 6 covers the connecting wire 4.

[0077] In this embodiment, a second insulating adhesive 6 is covered above the connecting line 4. When the solder ribbon 40 bends into the second gap 8, the second insulating adhesive 6 can support the solder ribbon 40, thereby reducing the degree of bending deformation of the solder ribbon 40 and thus reducing the risk of disconnection between the solder ribbon 40 and the solder pad 3 and damage to the solder ribbon 40.

[0078] like Figure 6 As shown, in the second direction Y, the width of the second insulating adhesive 6 is smaller than the width of the first insulating adhesive 5, thereby reducing the risk of the second insulating adhesive 6 contacting the adjacent second pad 32, reducing the risk of residual material on the second pad 32 due to the curing of the second insulating adhesive 6, and reducing the risk of the residual material causing positional displacement of the solder paste during the curing process, resulting in poor soldering of the solder ribbon 40. In other words, it reduces the risk of the second insulating adhesive 6 contacting the adjacent second pad 32, resulting in poor soldering of the solder ribbon 40 and the second pad 32, thereby improving the connection reliability between the solder ribbon 40 and the pad 3, and thus improving the performance of the back contact battery.

[0079] In some embodiments, such as Figure 6 As shown, in the first direction X, the second insulating adhesive 6 is connected to the first insulating adhesive 5 to increase the support effect of the second insulating adhesive 6 on the solder ribbon 40, and reduce the risk that part of the solder ribbon 40 in the first direction X is in contact with the second insulating adhesive 6 and the other part is suspended, causing the solder ribbon 40 to tilt.

[0080] Figure 7 This is a schematic diagram of the structure of the first insulating adhesive 5 and the second insulating adhesive 6 in some embodiments. Figure 8 for Figure 7 A schematic diagram of the structure of the second insulating adhesive 6. Also refer to... Figure 7 and Figure 8 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.

[0081] like Figure 8 As shown, in the second direction Y, the width of the first end 621 is smaller than the width of the second end 622, that is... Figure 8 As shown, the width of the connection end is a gradually decreasing value. That is, along the first direction X, from the first insulating adhesive 5 to the second insulating adhesive 6, the width of the connection end gradually decreases.

[0082] In this embodiment, the width of the connecting portion 62 on the side closer to the first insulating adhesive 5 is greater than the width on the side closer to the main body portion 61, thereby increasing the width 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.

[0083] like Figure 8 As shown, the connecting part 62 includes a first sidewall 623 and a second sidewall 624 disposed opposite to each other along the second direction Y. The first sidewall 623 and the second sidewall 624 can be constructed as straight surfaces or as curved surfaces.

[0084] In this embodiment, the first sidewall 623 and the second sidewall 624 are constructed as arc surfaces, so that the first insulating adhesive 5 and the second insulating adhesive 6 are connected by an arc transition. While increasing the connection area of ​​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.

[0085] 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 constructed as an integral structure or as a separate structure.

[0086] Figure 7 The example illustrates that the first insulating adhesive 5 and the second insulating adhesive 6 are constructed as separate units, i.e., the first insulating adhesive 5 and the second insulating adhesive 6 are formed in two steps to simplify the structure of the printing screen.

[0087] Figure 9 This is a schematic diagram of the structure of the first insulating adhesive 5 and the second insulating adhesive 6 in some other embodiments. For example... Figure 9 As shown, the first insulating adhesive 5 and the second insulating adhesive 6 are constructed as an integral structure, that is, the first insulating adhesive 5 and the second insulating adhesive 6 are integrally molded to simplify the processing of the first insulating adhesive 5 and the second insulating adhesive 6.

[0088] Figure 6 , Figure 7 and Figure 9 An example is shown of the connection between the first insulating adhesive 5 and the second insulating adhesive 6.

[0089] In other embodiments, the first insulating adhesive 5 and the second insulating adhesive 6 are not connected. Figure 10 for Figure 3 Enlarged view of part B in some other embodiments. Figure 11 for Figure 10 A schematic diagram of the structure of the first insulating adhesive 5 and the second insulating adhesive 6 in some other embodiments, while referring to... Figure 10 and Figure 11 The second insulating adhesive 6 and the first insulating adhesive 5 have a third gap 9 in the first direction X.

[0090] In this embodiment, the first insulating adhesive 5 and the second insulating adhesive 6 are not connected, which reduces the size of the second insulating adhesive 6 in the first direction X, which helps to reduce 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.

[0091] Take the connection of the first insulating adhesive 5 and the second insulating adhesive 6 as an example.

[0092] Figure 12 This is a schematic diagram of the structure of the first insulating adhesive 5 and the second insulating adhesive 6 in some other embodiments. For example... Figure 12 As shown, the first insulating adhesive 5 includes a first edge 51 and a second edge 52 disposed opposite to each other along the second direction Y, and the second insulating adhesive 6 includes a third edge 611 and a fourth edge 612 disposed opposite to each other along the second direction Y. The first edge 51 and the third edge 611 are located on the same side, the second edge 52 and the fourth edge 612 are located on the same side, and the first edge 51, the second edge 52, the third edge 611 and the fourth edge 612 are parallel.

[0093] In some embodiments, such as Figure 12 As 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 closer to the first edge 51.

[0094] Figure 13 This is a schematic diagram of the structure of the first insulating adhesive 5 and the second insulating adhesive 6 in some other embodiments. In other embodiments, such as Figure 13 As 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.

[0095] In this embodiment, the second insulating adhesive 6 is centrally positioned in the second direction Y, such that the distance between the second insulating adhesive 6 and the two adjacent second pads 32 is equal or approximately equal, reducing the risk that the connection between the second pad 32 and the solder ribbon 40 will fail due to the small distance between the second insulating adhesive 6 and the second pad 32 on one side.

[0096] Figure 14 This is a schematic diagram of the back contact battery and solder strip 40 in some embodiments. For example... Figure 14 As shown, on the third direction Z, the thickness of the second insulating adhesive 6 is equal to the thickness of the first insulating adhesive 5.

[0097] Figure 15 This is a schematic diagram of the back contact battery and solder strip 40 in some other embodiments. For example... Figure 15As shown, on the third direction Z, the thickness of the second insulating adhesive 6 is less than the thickness of the first insulating adhesive 5.

[0098] In this embodiment, the second insulating adhesive 6 is lower than the first insulating adhesive 5. When the solder ribbon 40 bends and deforms towards the second insulating adhesive 6, the second insulating adhesive 6 can still contact and support the solder ribbon 40, thereby reducing the deformation of the solder ribbon 40 and improving the connection stability between the solder ribbon 40 and the pad 3. The thickness of the second insulating adhesive 6 is less than the thickness of the first insulating adhesive 5, which reduces the size of the second insulating adhesive 6 in the third direction Z, thus helping to reduce the material cost of the second insulating adhesive 6.

[0099] 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, which reduces the risk of the second insulating adhesive 6 lifting the solder ribbon 40 and causing the solder ribbon 40 to be poorly soldered to the solder pad 3, thereby improving the connection stability between the solder ribbon 40 and the solder pad 3, which is beneficial to improving the performance of the back contact battery.

[0100] A second aspect of this application provides a back-contact stacked battery. Figure 16 The back-contact stacked battery provided in this application is illustrated in some embodiments as follows: Figure 16 As shown, the back contact stacked cell 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 and the back contact bottom cell 301 are electrically connected to the light-facing surface. The back contact bottom cell 301 is constructed as the back contact cell described above.

[0101] The perovskite top-mounted solar cell 302 is a thin-film solar cell using perovskite material as the photoactive layer. The structure of the perovskite top-mounted solar cell 302 mainly consists of the following key components: 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-mounted solar cell 302 to effectively absorb sunlight and convert it into electrical energy. The perovskite material in the light-absorbing layer has excellent light absorption performance, absorbing a wider spectral range and effectively converting short-wavelength spectra, giving the perovskite top-mounted solar cell 302 high photoelectric conversion efficiency.

[0102] A third aspect of the embodiments of this application provides a photovoltaic module. Figure 17 The following are schematic diagrams of the structure of the photovoltaic module provided in this application in some embodiments, such as... Figure 17 As shown, the photovoltaic module includes a cover plate 10, an encapsulation layer 20, and a cell layer 30.

[0103] The cover plate 10 includes a first cover plate 101 and a second cover plate 102 arranged along the third direction Z. The encapsulation layer 20 and the battery layer 30 are located between the first cover plate 101 and the second cover plate 102. A portion of the encapsulation layer 20 is located between the battery layer 30 and the first cover plate 101, and another portion of the encapsulation layer 20 is located between the battery layer 30 and the second cover plate 102, so as to achieve the encapsulation and fixation of the cover plate 10 and the battery layer 30.

[0104] At least one of the first cover plate 101 and the second cover plate 102 is made of a light-transmitting material, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0105] The first cover plate 101 can be made of one of the following rigid materials: tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the first cover plate 101 can be made of one of the following flexible materials: PVF (polyvinyl fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), or PVDF (polyvinylidene fluoride). All of these materials have high light transmittance, ensuring that more light reaches the battery layer, thereby increasing the light absorption of the photovoltaic module and improving its photoelectric conversion efficiency.

[0106] The material of the second cover plate 102 can be one of rigid materials such as tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the material of the second cover plate 102 can be one of flexible materials such as PVF (polyvinyl fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), or PVDF (polyvinylidene fluoride).

[0107] The materials of the first cover plate 101 and the second cover plate 102 can be the same or different.

[0108] like Figure 17 As shown, the encapsulation layer 20 includes a first adhesive film 201 and a second adhesive film 202. In the third direction Z, a portion of the structure of the first adhesive film 201 is located between the battery layer 30 and the first cover plate 101, and a portion of the structure of the second adhesive film 202 is located between the battery layer and the second cover plate 102.

[0109] The first film 201 is made of one of the following polyolefins: EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral). These materials have high light transmittance, which is beneficial to improving the photoelectric conversion efficiency of photovoltaic modules.

[0110] The material of the second adhesive film 202 is one of the polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral).

[0111] The materials of the first adhesive film 201 and the second adhesive film 202 can be the same or different.

[0112] The battery layer 30 contains multiple battery strings connected in series or in parallel. Each battery string consists of multiple battery cells (including but not limited to monocrystalline silicon battery cells and polycrystalline silicon battery cells) connected in series, and adjacent battery cells are connected by solder strips.

[0113] The battery cell can be either the back-contact battery described above or the back-contact stacked battery 303 described above.

[0114] The battery layer 30 may contain only the aforementioned back contact battery, or only the aforementioned back contact stacked battery 303, or both the aforementioned back contact battery and the aforementioned back contact stacked battery 303. In this application embodiment, there are no special limitations on the number, type, series and parallel connection method of the battery cells contained in the battery layer 30.

[0115] In this embodiment, two adjacent pads of the same polarity are electrically connected by a connecting line, which reduces the risk that the current of the grid line cannot be collected after the connection between the pad and the solder strip fails, thereby improving the output power of the back contact cell and the photovoltaic module with the back contact cell.

[0116] The grid line adjacent to the connecting line and with the opposite polarity to the connecting line is covered with a first insulating adhesive, which reduces the risk of short circuit of the back contact cell caused by solder strip misalignment and improves the performance of the back contact cell and the photovoltaic module with the back contact cell.

[0117] The connecting line is covered with a second insulating adhesive, which supports the solder ribbon and reduces the degree of bending deformation of the solder ribbon. This reduces the risk of the solder ribbon breaking off from the pad and the solder ribbon being damaged, thereby improving the performance of the back contact cell and the photovoltaic module with the back contact cell.

[0118] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A back-contact battery, characterized in that, The back contact battery includes: Ontology(1); A grid line (2) extending along a first direction (X) is located on the back surface of the body (1), and a plurality of grid lines (2) are arranged at intervals along a second direction (Y); Pads (3) are connected to the gate lines (2), and a plurality of pads (3) are arranged at intervals along the second direction (Y); The connecting line (4) is in the second direction (Y), and its two ends are respectively connected to the adjacent pads (3); The grid line (2) includes a first grid line (21), the first grid line (21) and the connecting line (4) are arranged in the first direction (X), and the end of the first grid line (21) and the connecting line (4) are separated by a first gap (7) in the first direction (X). A first insulating adhesive (5) and a second insulating adhesive (6) are arranged along 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 connecting 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 part (61) and a connecting part (62); The connecting part (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 part (61), and the second end (622) is 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 sidewall (623) and a second sidewall (624) disposed opposite to each other along the second direction (Y), and the first sidewall (623) and the second sidewall (624) are constructed 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 constructed as an integral structure.

6. The back contact battery according to claim 1, characterized in that, The second insulating adhesive (6) and the first insulating adhesive (5) have a third gap (9) 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) disposed opposite to each other along the second direction (Y), and the second insulating adhesive (6) includes a third edge (611) and a fourth edge (612) disposed opposite to each other 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 battery, characterized in that, The back-contact stacked battery (303) includes: A back-contact bottom battery (301), said back-contact bottom battery (301) being configured as a back-contact battery according to any one of claims 1 to 8; A perovskite top cell (302) is 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 battery layer (30). The battery layer (30) includes a plurality of back-contact batteries as described in any one of claims 1 to 8, and / or the battery layer (30) includes a plurality of back-contact stacked batteries (303) as described in claim 9.

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