Back contact cells, back contact tandem cells and photovoltaic modules

Abstract

This application relates to the photovoltaic field, providing a back-contact cell, a back-contact tandem cell, and a photovoltaic module. The back-contact cell includes a body, with a main grid and fine grids disposed on the back surface of the body. The main grid includes a first main grid and a second main grid alternately distributed along a first direction, and the fine grids include a first fine grid and a second fine grid alternately distributed along a second direction. The first fine grids are spaced apart from the second main grids, and the second fine grids are spaced apart from the first main grids. A first insulating member includes a first covering portion and a first connecting portion connected to each other. The first covering portion has first connecting portions on both sides along the first direction, and along the second direction, the width of the first covering portion is smaller than the width of the first connecting portion. The first covering portion at least partially covers the main grids, and the two first connecting portions respectively cover the ends of the fine grids located on both sides of the main grids and spaced apart from them. This not only improves the structural stability and yield of the back-contact cell but also reduces the material usage of the first insulating member.

Description

Technical Field

[0001] This application relates to the photovoltaic field, specifically to a back-contact battery, a back-contact tandem battery, and a photovoltaic module. Background Technology

[0002] In back-contact solar cells, both the positive and negative grid lines are located on the back side, leaving the light-facing side unobstructed by grid lines. Compared to conventional photovoltaic cells, this reduces light energy loss due to grid line shading, resulting in higher photoelectric conversion efficiency. When multiple back-contact solar cells are assembled into a photovoltaic module, solder ribbons are typically used to connect the grid lines of adjacent cells.

[0003] To prevent short circuits caused by the solder ribbon connecting grid lines of different polarities, an insulating component is required on the grid lines of the opposite polarity to the solder ribbon. The structure of the insulating component affects the connection between the solder ribbon and the grid lines, as well as the stress on the cell during the connection. Existing insulation structures have certain defects, which may lead to excessive bending of the solder ribbon and grid line breakage, affecting the structural stability of the back contact cell and thus impacting its efficiency and yield. Summary of the Invention

[0004] In view of this, this application provides a back-contact battery, a back-contact tandem battery, and a photovoltaic module to help solve the problem of insufficient structural stability of back-contact batteries in the prior art.

[0005] In a first aspect, embodiments of this application provide a back-contact battery, comprising: a body, wherein a main grid and fine grids are disposed on the back surface of the body, the main grid including a first main grid and a second main grid alternately distributed along a first direction, and the fine grids including a first fine grid and a second fine grid alternately distributed along a second direction, the first fine grids being spaced apart from the second main grids, and the second fine grids being spaced apart from the first main grids; a first insulating member, the first insulating member including a first covering portion and a first connecting portion connected to each other, the first covering portion having a first connecting portion disposed on both sides along the first direction, and the width of the first covering portion being smaller than the width of the first connecting portion along the second direction; at least a portion of the first covering portion covers the main grid, and two first connecting portions respectively cover the ends of the fine grids located on both sides of the main grid and spaced apart from the main grid; the first direction intersects the second direction.

[0006] In one possible implementation, along the second direction, the width of the first covering portion is W1, and the width of the first connecting portion is W2, wherein W1 and W2 satisfy: 1 ​​< W2 : W1 ≤ 4.

[0007] In one possible implementation, the width W1 of the first covering portion is 0.2 mm to 0.6 mm.

[0008] In one possible implementation, the length L1 of the first covering portion along the first direction is 0.1 mm to 0.8 mm.

[0009] In one possible implementation, the first insulating member further includes a first extension that covers the fine grid; along the first direction, the first extension is connected to the end of the first connecting portion away from the first covering portion.

[0010] In one possible implementation, along the second direction, the width W3 of the first extension is less than or equal to the width W2 of the first connection.

[0011] In one possible implementation, the back contact battery further includes a pad and a second insulating member, the pad being connected to the main grid; along the second direction, the second insulating member is located on the side of the first insulating member closer to the pad; the second insulating member includes a second connecting portion and a protrusion connected together, at least a portion of the second connecting portion covering the main grid, and along the first direction, both ends of the second connecting portion respectively covering the ends of the fine grid located on both sides of the main grid and spaced apart from the main grid; the protrusion extends along the second direction, at least a portion of the protrusion covering the fine grid located between the pad and the second insulating member and connected to the main grid.

[0012] In one possible implementation, the width W4 of the protrusion along the first direction is 0.1 mm to 0.8 mm.

[0013] In one possible implementation, the length L2 of the protrusion along the second direction is 0.1 mm to 1.2 mm.

[0014] In one possible implementation, the back contact battery further includes a pad and a third insulating element, the pad being connected to the main grid; along the second direction, the third insulating element is located on the side of the first insulating element away from the pad; the third insulating element includes two third connecting portions, the two third connecting portions being respectively disposed on both sides of the main grid along the first direction, and the two third connecting portions respectively covering the ends of the fine grids spaced apart from the main grid.

[0015] Secondly, embodiments of this application provide a back-contact stacked solar cell, including a back-contact bottom cell and a perovskite top cell, wherein the perovskite top cell and the light-facing surface of the back-contact bottom cell are electrically connected; the back-contact bottom cell includes: a body, wherein the back-facing surface of the body is provided with a main grid and a fine grid, the main grid including a first main grid and a second main grid alternately distributed along a first direction, the fine grid including a first fine grid and a second fine grid alternately distributed along a second direction, the first fine grid being spaced apart from the second main grid, and the second fine grid being spaced apart from the first main grid; a first insulating member, the first insulating member including a first covering portion and a first connecting portion connected together, the first covering portion having a first connecting portion on both sides along the first direction, and the width of the first covering portion being smaller than the width of the first connecting portion along the second direction; at least part of the first covering portion covers the main grid, and two first connecting portions respectively cover the ends of the fine grid located on both sides of the main grid and spaced apart from the main grid; the first direction intersects the second direction.

[0016] Thirdly, embodiments of this application provide a photovoltaic module, including: a plurality of photovoltaic cells, wherein the photovoltaic cells are back-contact cells as described above, or the photovoltaic cells are back-contact tandem cells as described above; and a solder strip, wherein the main grids of two adjacent photovoltaic cells along the second direction are connected by the solder strip.

[0017] The beneficial effects of this application are as follows: The first connecting portion covers the end of the fine grid break to ensure insulation between the main grid and the fine grid of opposite polarity. Simultaneously, the first connecting portion also prevents the solder ribbon connected to the main grid from contacting the end of the fine grid break and forming an electrical connection with it, thereby reducing the risk of short circuits in the back contact cell due to solder ribbon misalignment. This improves the structural reliability of the back contact cell and also increases the yield rate of photovoltaic modules. The first covering portion at least partially covers the main grid. When the solder ribbon is laid on the main grid, the first covering portion can support and lift the solder ribbon, reducing the height difference between the corresponding part of the solder ribbon and the pad and other adjacent parts. This reduces the possibility of excessive local bending of the solder ribbon, which helps reduce the risk of open or incomplete soldering when welding the solder ribbon to the main grid, and also helps reduce the risk of warping of the back contact cell. Along the second direction, when multiple first covering portions are spaced apart on the same main grid, the solder strip is raised as a whole, resulting in more uniform stress distribution across the entire solder strip during welding. This helps reduce the risk of solder strip deformation and the stress exerted on the main and fine grids, thus reducing the risk of breakage and improving the structural reliability of the back contact battery. Along the second direction, when the width of the first covering portion is smaller than the width of the first connecting portion, the first insulating component has a structure that is narrow in the middle and wide at both ends. This reduces the amount of raw materials used in the first insulating component, thus lowering the manufacturing cost of the back contact battery. Furthermore, the first insulating component is typically obtained by printing insulating adhesive onto the main and fine grids using a screen printing plate. When the first insulating component is designed with a narrow-in-the-middle and wide-at-both-ends structure, the alignment of the printing mesh openings on the screen printing plate with the main grid position can be quickly determined to ensure accurate positioning of the screen printing plate. This improves the printing efficiency and accuracy of the first insulating component, thereby increasing the production efficiency of the back contact battery. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a schematic diagram of the back surface of the back contact battery provided in an embodiment of this application;

[0020] Figure 2 for Figure 1 A partial structural diagram of the back contact battery in the diagram;

[0021] Figure 3 for Figure 2 A partial structural diagram of the back contact battery in the diagram;

[0022] Figure 4 for Figure 2 A partial structural diagram of the back contact battery in another embodiment;

[0023] Figure 5 for Figure 4 A partial structural diagram of the back contact battery in the diagram;

[0024] Figure 6 for Figure 2 Another partial structural diagram of the back contact battery in the diagram;

[0025] Figure 7 for Figure 4 Another partial structural diagram of the back contact battery in the diagram;

[0026] Figure 8 This is a schematic diagram of the structure of the back contact stacked battery provided in the embodiments of this application;

[0027] Figure 9 This is a schematic diagram of the structure of the photovoltaic module provided in the first embodiment of this application;

[0028] Figure 10 This is a schematic diagram of the structure of the photovoltaic module provided in the second embodiment of this application.

[0029] Figure label:

[0030] 10-Back contact battery;

[0031] 20-Back contact stacked battery;

[0032] 201-Back contact bottom battery;

[0033] 202-Perovskite Top Cell;

[0034] 30 - Welding strip;

[0035] 40-front plate;

[0036] 50 - Front encapsulation layer;

[0037] 60 - Backside encapsulation layer;

[0038] 70 - Backplate;

[0039] 1-Ontology;

[0040] 2-Main gate;

[0041] 21 - First main gate;

[0042] 22 - Second main gate;

[0043] 3-Fine grid

[0044] 31 - First fine grid;

[0045] 32 - Second fine grid;

[0046] 4-First insulating element;

[0047] 41-First Covering Section;

[0048] 42-First connecting part;

[0049] 43-First extension;

[0050] 5-Second insulating component;

[0051] 51-Second connecting part;

[0052] 52 - Protrusion;

[0053] 53-Second extension;

[0054] 6-Third insulating component;

[0055] 61-Third connecting part;

[0056] 62-Third extension;

[0057] 7-Pads;

[0058] 71 - First pad;

[0059] 72 - Second pad;

[0060] 8-Edge grid lines

[0061] 9-Fourth insulating component;

[0062] 91-Fourth connecting part;

[0063] 92-Fourth extension. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0069] This application provides a back contact battery 10, such as Figure 1 As shown, the back contact battery 10 includes a body 1. The back surface of the body 1 is provided with a main grid 2 and a fine grid 3. The main grid 2 includes a first main grid 21 and a second main grid 22 alternately distributed along a first direction X, and both the first main grid 21 and the second main grid 22 extend along a second direction Y. The fine grid 3 includes a first fine grid 31 and a second fine grid 32 alternately distributed along the second direction Y, and both the first fine grid 31 and the second fine grid 32 extend along the first direction X, used to collect and guide the photocurrent generated in the body 1. The first fine grid 31 intersects with the first main grid 21 and forms an electrical connection, so that the first main grid 21 can collect and output the photocurrent collected by the first fine grid 31. The second fine grid 32 intersects with the second main grid 22 and forms an electrical connection, so that the second main grid 22 can collect and output the photocurrent collected by the second fine grid 32.

[0070] It should be noted that the first direction X intersects with the second direction Y, such as... Figure 1 As shown, one of the first direction X and the second direction Y can be the length direction of the back contact battery 10, and the other can be the width direction of the back contact battery 10.

[0071] In this embodiment, the first main gate 21 and the second main gate 22 have opposite polarities; one is the positive main gate of the back contact battery 10, and the other is the negative main gate of the back contact battery 10. The first fine gate 31 has the same polarity as the first main gate 21, and the second fine gate 32 has the same polarity as the second main gate 22. The first fine gate 31 and the second main gate 22 are spaced apart, that is, the first fine gate 31 is disconnected at the second main gate 22 to avoid short circuit due to electrical connection between the first fine gate 31 and the second main gate 22. The second fine gate 32 is spaced apart from the first main gate 21, that is, the second fine gate 32 is disconnected at the first main gate 21 to avoid short circuit due to electrical connection between the second fine gate 32 and the first main gate 21. Figure 1 As shown, the back contact battery 10 is further provided with edge grid lines 8 at both ends along the first direction X, and the edge grid lines 8 extend along the second direction Y. The polarity of the edge grid lines 8 is opposite to that of the adjacent main grid 2, and is used to intersect and electrically connect with the fine grids 3 that are interrupted by the main grid 2, so as to collect the current collected by the interrupted fine grids 3 and collect the current to the uninterrupted fine grids 3 connected to the main grid 2, thereby improving the efficiency of the back contact battery 10. The polarities of the two edge grid lines 8 located at both ends of the back contact battery 10 along the first direction X can be the same or opposite, and this embodiment does not limit this.

[0072] It should be noted that the accompanying drawings provided in this application use lines of different thicknesses to distinguish the first fine gate 31 and the second fine gate 32. This is not a limitation on the relative width between the first fine gate 31 and the second fine gate 32. The width of the first fine gate 31 and the width of the second fine gate 32 may be equal or unequal. Similarly, the width of the edge gate line 8, the width of the first main gate 21, and the width of the second main gate 22 may be equal or unequal.

[0073] When multiple back-contact cells 10 form a photovoltaic module, adjacent back-contact cells 10 are electrically connected using solder strips. One end of the solder strip is electrically connected to the first main busbar 21 of one of the back-contact cells 10, and the other end is electrically connected to the second main busbar 22 of the other back-contact cell 10. For example... Figure 2As shown, the back contact battery 10 also includes pads 7, which include a first pad 71 and a second pad 72. The first pad 71 is connected to and electrically connected to the first main grid 21, and the second fine grid 32 is disconnected at the first pad 71. The solder strip is electrically connected to the first main grid 21 by welding it to the first pad 71 to collect the current on the first main grid 21. The second pad 72 is connected to and electrically connected to the second main grid 22, and the first fine grid 31 is disconnected at the second pad 72. The solder strip is electrically connected to the second main grid 22 by welding it to the second pad 72 to collect the current on the second main grid 22. One first main grid 21 can be provided with multiple first pads 71, and one second main grid 22 can be provided with multiple second pads 72. In this embodiment, the number of first pads 71 ​​and the number of second pads 72 are not limited.

[0074] Since the width of the solder strip is usually larger than the width of the main grid 2, in order to avoid the solder strip from coming into contact with the fine grid 3 located on both sides of the main grid 2 and having the opposite polarity to the main grid 2 and forming a short circuit, the back contact battery 10 provided in this embodiment also includes an insulating component. The insulating component is disposed on the back surface of the body 1 and is used to form an insulating effect between the main grid 2 and the fine grid 3 with opposite polarities. This embodiment takes insulating adhesive as an example for explanation.

[0075] In some embodiments, combined with Figure 2 and Figure 3 As shown, the insulating component includes at least a first insulating component 4. The first insulating component 4 includes a first covering portion 41 and a first connecting portion 42 connected together. The first covering portion 41 has first connecting portions 42 on both sides along the first direction X. At least a portion of the first covering portion 41 covers the main grid 2, and the two first connecting portions 42 respectively cover the ends of the fine grids 3 located on both sides of the main grid 2 and spaced apart from the main grid 2. The main grid 2 is one of a first main grid 21 and a second main grid 22, and the fine grid 3 is one of a first fine grid 31 and a second fine grid 32.

[0076] In this embodiment, the first connecting portion 42 covers the end of the fine grid 3 at the break point to ensure insulation between the main grid 2 and the fine grid 3 of opposite polarities. Simultaneously, the first connecting portion 42 also prevents the solder ribbon connected to the main grid 2 from contacting the end of the fine grid 3 at the break point and forming an electrical connection with it. This reduces the risk of short circuits in the back contact cell 10 due to solder ribbon misalignment, improving the structural reliability of the back contact cell 10 and increasing the yield rate of the photovoltaic module.

[0077] Since the height of pad 7 is usually higher than the height of main gate 2, when the solder ribbon is laid on main gate 2, the position of the solder ribbon corresponding to pad 7 will be raised by pad 7. Moreover, in order to improve the soldering effect between the solder ribbon and pad 7, solder paste is usually applied to pad 7. This will increase the height difference between the part where the solder ribbon and pad 7 are connected and other adjacent parts, resulting in a greater degree of local bending of the solder ribbon. This makes it easy for the solder ribbon to have open or cold solder joints when soldering to main gate 2, and the back contact cell 10 is also prone to warping, resulting in a decrease in the yield and efficiency of the back contact cell 10. In this embodiment, at least a portion of the first covering part 41 covers the main grid 2. When the solder ribbon is laid on the main grid 2, the first covering part 41 can lift and support the solder ribbon, reducing the height difference between the corresponding part of the solder ribbon and the pad 7 and other adjacent parts. This reduces the possibility of excessive local bending of the solder ribbon, which helps to reduce the risk of open or incomplete soldering when the solder ribbon is welded to the main grid 2, and also helps to reduce the risk of warping of the back contact battery 10. Along the second direction Y, when multiple first covering parts 41 are spaced apart on the same main grid 2, the solder ribbon is raised as a whole, and the stress on the entire solder ribbon is more uniform during welding. This helps to reduce the risk of solder ribbon deformation, and also helps to reduce the stress applied by the solder ribbon to the main grid 2 and the fine grid 3, reducing the risk of breakage of the main grid 2 and the fine grid 3, thereby improving the structural reliability of the back contact battery 10.

[0078] like Figure 3 As shown, along the second direction Y, the width W1 of the first covering portion 41 is smaller than the width W2 of the first connecting portion 42, meaning the first insulating member 4 has a structure that is narrow in the middle and wide at both ends. This reduces the amount of raw materials used in the first insulating member 4, which helps to reduce the manufacturing cost of the back contact battery 10. On the other hand, the first insulating member 4 is usually obtained by printing insulating adhesive onto the main grid 2 and the fine grid 3 using a printing screen. When the first insulating member 4 is set to a structure that is narrow in the middle and wide at both ends, by observing whether the position of the printing mesh on the printing screen used to print the first covering portion 41 is aligned with the position of the main grid 2, it is possible to quickly determine whether the positioning of the printing screen is accurate. This helps to improve the printing efficiency and printing accuracy of the first insulating member 4, thereby improving the production efficiency of the back contact battery 10.

[0079] In one specific embodiment, the width W1 of the first covering portion 41 and the width W2 of the first connecting portion 42 satisfy the following condition: 1 < W2: W1 ≤ 4. When the ratio of W2 to W1 meets this range, the widths of the first covering portion 41 and the first connecting portion 42 can be kept within a reasonable range: the width W1 of the first covering portion 41 will not be too small, ensuring the structural reliability and stability of the first covering portion 41 and preventing breakage; the width W2 of the first connecting portion 42 will not be too large, improving the insulation effect between the fine grid 3 with opposite polarity and the main grid 2, while also ensuring a suitable spacing between the first insulating member 4 and the fine grid 3 or pad 7 adjacent along the second direction Y, avoiding affecting the connection stability and reliability of the solder strip. In addition, when the ratio of W2 to W1 meets the above range, it can also save raw materials for the first insulating member 4, thereby reducing the manufacturing cost of the back contact battery 10, and also reducing the risk of the back contact battery 10 warping due to volume shrinkage of the first insulating member 4 during the curing process.

[0080] Optionally, the value of W2:W1 satisfies: 1 < W2:W1 ≤ 2. The value of W2:W1 can be 1.01, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95 or 2, or other values ​​within the above range. This embodiment does not impose any restrictions on this.

[0081] Optionally, the values ​​of W2:W1 satisfy: 2≤W2:W1≤3. The values ​​of W2:W1 can be 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, or 3, or other values ​​within the above range. This embodiment does not impose any restrictions on these values.

[0082] Optionally, the value of W2:W1 satisfies: 3≤W2:W1≤4. The value of W2:W1 can be 3, 3.05, 3.1, 3.15, 3.2, 3.25, 3.3, 3.35, 3.4, 3.45, 3.5, 3.55, 3.6, 3.65, 3.7, 3.75, 3.8, 3.85, 3.9, 3.95 or 4, or other values ​​within the above range. This embodiment does not impose any restrictions on this.

[0083] In some embodiments, the width W1 of the first covering portion 41 is 0.2mm to 0.6mm. In this case, the width range of the first covering portion 41 is reasonable: the width of the first covering portion 41 is not too small, ensuring that the first covering portion 41 is not easily broken, so that the first covering portion 41 and the first connecting portion 42 can form a reliable connection. At the same time, the area of ​​the first covering portion 41 is increased, so that the first covering portion 41 can provide stable support for the solder ribbon. The width of the first covering portion 41 is not too large, which can save raw materials for the first insulating member 4, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the first insulating member 4 during the curing process.

[0084] Optionally, the width W1 of the first covering portion 41 is 0.2mm to 0.3mm. W1 can be 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm or 3mm, or other values ​​within the above range. This embodiment does not limit this value.

[0085] Optionally, the width W1 of the first covering part 41 is 0.3mm to 0.4mm. W1 can be 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm or 4mm, or other values ​​within the above range. This embodiment does not limit this value.

[0086] Optionally, the width W1 of the first covering part 41 is 0.4mm to 0.5mm. W1 can be 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0087] Optionally, the width W1 of the first covering part 41 is 0.5mm to 0.6mm. W1 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0088] In some embodiments, the width W2 of the first connecting portion 42 is 0.3mm to 0.8mm. In this case, the width range of the first connecting portion 42 is reasonable: the width of the first connecting portion 42 is not too small, ensuring that the first connecting portion 42 can cover the end of the fine grid 3, so as to improve the insulation effect of the first connecting portion 42. The width of the first connecting portion 42 is not too large, which can save the raw materials of the first insulating member 4, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the first insulating member 4 during the curing process.

[0089] Optionally, the width W2 of the first connecting portion 42 is 0.3mm to 0.5mm. W2 can be 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0090] Optionally, the width W2 of the first connecting portion 42 is 0.5mm to 0.8mm. W2 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm or 8mm, or other values ​​within the above range. This embodiment does not limit this value.

[0091] In some embodiments, such as Figure 3 As shown, along the first direction X, the length L1 of the first covering portion 41 is 0.1mm to 0.8mm. This length range is reasonable: the length of the first covering portion 41 is not too large, saving raw materials for the first insulating component 4, reducing the manufacturing cost of the back contact battery 10, and reducing the risk of warping of the back contact battery 10 due to volume shrinkage of the first insulating component 4 during curing. The length of the first covering portion 41 is not too small, increasing its area so that it can provide stable support for the solder strip and act as a buffer during the solder strip welding process, reducing the stress on the main grid 2 within the area covered by the first covering portion 41, thereby reducing the risk of breakage of the main grid 2. Optionally, the length of the first covering portion 41 is greater than the width of the solder strip in the first direction X to reduce the risk of stress concentration caused by contact between the solder strip and the edge of the first connecting portion 42.

[0092] Optionally, the length L1 of the first covering portion 41 is 0.1mm to 0.3mm. L1 can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm or 3mm, or other values ​​within the above range. This embodiment does not limit this value.

[0093] Optionally, the length L1 of the first covering portion 41 is 0.3mm to 0.5mm. L1 can be 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm or 5mm, or other values ​​within the above range. This embodiment does not limit this.

[0094] Optionally, the length L1 of the first covering portion 41 is 0.5mm to 0.8mm. L1 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm or 8mm, or other values ​​within the above range. This embodiment does not limit this value.

[0095] It should be noted that, in different first insulating members 4, the ratio of W2 to W1 can be equal or unequal. In different first insulating members 4, the width W1 of the first covering portion 41 can be equal or unequal. In different first insulating members 4, the length L1 of the first covering portion 41 can be equal or unequal. In different first insulating members 4, the width of the first connecting portion 42 can be equal or unequal.

[0096] In some embodiments, such as Figure 4 and Figure 5 As shown, the first insulating member 4 also includes a first extension 43, which extends along the first direction X and is connected to the end of the first connecting portion 42 away from the first covering portion 41. The first extension 43 covers the fine grid 3. By providing the first extension 43, the total area of ​​the first insulating member 4 can be increased, thereby improving the insulation reliability of the first insulating member 4. Moreover, the first extension 43 covering the fine grid 3 can also provide a certain degree of protection for the fine grid 3, buffering external impact forces and reducing the risk of breakage of the fine grid 3.

[0097] Along the second direction Y, the width W3 of the first extension 43 is less than or equal to the width W2 of the first connecting portion 42. When the width W3 of the first extension 43 is equal to the width W2 of the first connecting portion 42, printing is easier, which helps to reduce the manufacturing difficulty of the first insulating member 4 and improve the production efficiency of the back contact battery 10. When the width W3 of the first extension 43 is less than the width W2 of the first connecting portion 42, the raw materials of the first insulating member 4 can be saved, the manufacturing cost of the back contact battery 10 can be reduced, and the risk of warping of the back contact battery 10 due to volume shrinkage of the first insulating member 4 during the curing process can also be reduced.

[0098] In some embodiments, the width W3 of the first extension 43 is 0.2mm to 0.6mm. In this case, the width range of the first extension 43 is reasonable: the width of the first extension 43 is not too small, making it less prone to breakage, so that the first extension 43 and the first connecting portion 42 can form a reliable connection. The width of the first extension 43 is not too large, which can save raw materials for the first insulating member 4, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the first insulating member 4 during the curing process.

[0099] Optionally, the width W3 of the first extension 43 is 0.2mm to 0.3mm. W3 can be 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm or 3mm, or other values ​​within the above range. This embodiment does not limit this value.

[0100] Optionally, the width W3 of the first extension 43 is 0.3mm to 0.4mm. W3 can be 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm or 4mm, or other values ​​within the above range. This embodiment does not limit this value.

[0101] Optionally, the width W3 of the first extension 43 is 0.4mm to 0.5mm. W3 can be 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0102] Optionally, the width W3 of the first extension 43 is 0.5mm to 0.6mm. W3 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0103] It should be noted that when the width W3 of the first extension 43 is less than the width W2 of the first connecting portion 42, within the same first insulating member 4, the width W3 of the first extension 43 and the width W1 of the first covering portion 41 may be equal or unequal. In different first insulating members 4, the width W3 of the first extension 43 may be equal or unequal. In different first insulating members 4, the length of the first extension 43 may be equal or unequal.

[0104] In some embodiments, such as Figure 2 and Figure 6 As shown, the insulating component also includes a second insulating component 5. Along the second direction Y, the second insulating component 5 is located on the side of the first insulating component 4 near the pad 7. The second insulating component 5 includes a second connecting portion 51 and a protrusion 52 connected together. At least a portion of the second connecting portion 51 covers the main grid 2. Along the first direction X, both ends of the second connecting portion 51 cover the ends of the fine grids 3 located on both sides of the main grid 2 and spaced apart from the main grid 2. The second connecting portion 51 covers the ends of the fine grids 3 at the break points to ensure the insulation effect between the main grid 2 and the fine grids 3 of opposite polarities. At the same time, the second connecting portion 51 can also prevent the solder ribbon connected to the main grid 2 from contacting the ends of the fine grids 3 at the break points and forming an electrical connection with the fine grids 3, thereby reducing the risk of short circuit of the back contact cell 10 due to solder ribbon misalignment. This is beneficial to improving the structural reliability of the back contact cell 10 and also to improving the yield of photovoltaic modules. When the solder ribbon is laid on the main grid 2, the second connecting part 51 can padded and support the solder ribbon, reducing the height difference between the corresponding part of the solder ribbon and the pad 7 and other adjacent parts, so as to reduce the excessive local bending of the solder ribbon. This helps to reduce the risk of open or incomplete soldering when the solder ribbon is welded to the main grid 2, and also helps to reduce the risk of warping of the back contact battery 10.

[0105] The protrusion 52 extends along the second direction Y toward the pad 7. At least a portion of the protrusion 52 covers the fine grid 3 located between the pad 7 and the second insulating member 5 and connected to the main gate 2. In other words, the protrusion 52 provides protection for the first fine grid 3 near the pad 7. Since the first fine grid 3 near the pad 7 experiences greater stress from the solder strip, the protrusion 52 helps reduce the risk of the fine grid 3 being broken by the solder strip, thereby ensuring the structural stability and photoelectric conversion efficiency of the back contact battery 10. Along the second direction Y, at least one side of the pad 7 is provided with the second insulating member 5.

[0106] In one embodiment, if Figure 6 As shown, along the first direction X, the width W4 of the protrusion 52 is 0.1mm to 0.8mm. This width range is reasonable: the width of the protrusion 52 is not too small, ensuring it is not easily broken, thus allowing for a reliable connection between the protrusion 52 and the second connecting part 51. Simultaneously, the increased area of ​​the protrusion 52 provides stable support for the solder strip and acts as a buffer during solder strip welding, reducing the stress on the main grid 2 and fine grid 3 within the area covered by the protrusion 52, thereby reducing the risk of breakage of the main grid 2 and fine grid 3. The width of the protrusion 52 is not too large, saving raw materials for the second insulating component 5, reducing the manufacturing cost of the back contact battery 10, and also reducing the risk of warping of the back contact battery 10 due to volume shrinkage of the second insulating component 5 during curing.

[0107] Optionally, the width W4 of the protrusion 52 is 0.1mm to 0.3mm. W4 can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm or 3mm, or other values ​​within the above range. This embodiment does not limit this value.

[0108] Optionally, the width W4 of the protrusion 52 is 0.3mm to 0.5mm. W4 can be 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0109] Optionally, the width W4 of the protrusion 52 is 0.5mm to 0.8mm. W4 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm or 8mm, or other values ​​within the above range. This embodiment does not limit this value.

[0110] In some embodiments, the length L2 of the protrusion 52 along the second direction Y is 0.1mm to 1.2mm. In this case, the length range of the protrusion 52 is reasonable: the length of the protrusion 52 is not too large to ensure a gap of 0.1mm to 0.5mm between the protrusion 52 and the pad 7, avoiding the protrusion 52 affecting the connection reliability between the solder ribbon and the pad 7. It also saves raw materials for the second insulating member 5, reduces the manufacturing cost of the back contact battery 10, and reduces the risk of warping of the back contact battery 10 due to volume shrinkage of the second insulating member 5 during curing. The length of the protrusion 52 is not too small so that it can cover a portion of the first fine grid 3 near the pad 7, improving the protective effect of the second insulating member 5 on the fine grid 3. The area of ​​the protrusion 52 can also be appropriately increased so that it can provide stable support for the solder ribbon and act as a buffer during the soldering process.

[0111] Optionally, the length L2 of the protrusion 52 is 0.1mm to 0.4mm. L2 can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm or 0.4mm, or other values ​​within the above range. This embodiment does not limit this value.

[0112] Optionally, the length L2 of the protrusion 52 is 0.4mm to 0.8mm. L2 can be 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm or 0.8mm, or other values ​​within the above range. This embodiment does not limit this.

[0113] Optionally, the length L2 of the protrusion 52 is 0.8mm to 1.2mm. L2 can be 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm or 1.2mm, or other values ​​within the above range. This embodiment does not limit this.

[0114] In other embodiments, the protrusion 52 may not cover the fine gate 3 located between the pad 7 and the second insulating member 5 and connected to the main gate 2. That is, the protrusion 52 only serves to support the solder strip and does not directly protect the fine gate 3.

[0115] In some embodiments, along the second direction Y, the width W5 of the second connecting portion 51 is 0.3mm to 0.8mm. In this case, the width range of the second connecting portion 51 is reasonable: the width of the second connecting portion 51 is not too small, ensuring that the second connecting portion 51 can cover the end of the fine grid 3, thereby improving the insulation effect of the second connecting portion 51. The width of the second connecting portion 51 is not too large, which can save raw materials for the second insulating member 5, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the second insulating member 5 during the curing process.

[0116] Optionally, the width W5 of the second connecting portion 51 is 0.3mm to 0.5mm. W5 can be 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0117] Optionally, the width W5 of the second connecting portion 51 is 0.5mm to 0.8mm. W5 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm or 8mm, or other values ​​within the above range. This embodiment does not limit this value.

[0118] In some embodiments, such as Figure 7 As shown, the second insulating member 5 also includes a second extension 53, which extends along the first direction X. The second connecting portion 51 is connected to the second extension 53 at both ends along the first direction X. The second extension 53 covers the fine grid 3. By providing the second extension 53, the total area of ​​the second insulating member 5 can be increased, improving the insulation reliability of the second insulating member 5. Furthermore, the second extension 53 covering the fine grid 3 can also provide some protection for the fine grid 3, buffering external impacts and reducing the risk of breakage of the fine grid 3.

[0119] Along the second direction Y, the width W6 of the second extension 53 is less than or equal to the width W5 of the second connecting portion 51. When the width W6 of the second extension 53 is equal to the width W5 of the second connecting portion 51, printing is easier, which helps reduce the manufacturing difficulty of the second insulating member 5 and improves the production efficiency of the back contact battery 10. When the width W6 of the second extension 53 is less than the width W5 of the second connecting portion 51, the raw materials of the second insulating member 5 can be saved, the manufacturing cost of the back contact battery 10 can be reduced, and the risk of warping of the back contact battery 10 due to volume shrinkage of the second insulating member 5 during the curing process can also be reduced.

[0120] In some embodiments, the width W6 of the second extension 53 is 0.2mm to 0.6mm. In this case, the width range of the second extension 53 is reasonable: the width of the second extension 53 is not too small, making it less prone to breakage, so that the second extension 53 and the second connecting portion 51 can form a reliable connection. The width of the second extension 53 is not too large, which can save raw materials for the second insulating member 5, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the second insulating member 5 during the curing process.

[0121] Optionally, the width W6 of the second extension 53 is 0.2mm to 0.3mm. W6 can be 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm or 3mm, or other values ​​within the above range. This embodiment does not limit this value.

[0122] Optionally, the width W6 of the second extension 53 is 0.3mm to 0.4mm. W6 can be 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm or 4mm, or other values ​​within the above range. This embodiment does not limit this value.

[0123] Optionally, the width W6 of the second extension 53 is 0.4mm to 0.5mm. W6 can be 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0124] Optionally, the width W6 of the second extension 53 is 0.5mm to 0.6mm. W6 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm or 5mm, or other values ​​within the above range. This embodiment does not limit this value.

[0125] It should be noted that, in different second insulating members 5, the width W6 of the second extension 53 may be equal or unequal. In different second insulating members 5, the width W5 of the second connecting part 51 may be equal or unequal. In different second insulating members 5, the width W4 and the length L2 of the protrusion 52 may be equal or unequal.

[0126] In some embodiments, such as Figure 2 As shown, the insulating component also includes a third insulating component 6, which is located on the side of the first insulating component 4 away from the pad 7 along the second direction Y. The third insulating component 6 includes two third connecting portions 61, which are respectively disposed on both sides of the main gate 2 along the first direction X, and respectively cover the ends of the fine gates 3 that are spaced apart from the main gate 2.

[0127] In this embodiment, since the third insulating member 6 is far away from the pad 7 relative to the first insulating member 4 and / or the second insulating member 5, the portion of the solder strip corresponding to the position of the third insulating member 6 has a smaller stress effect on the back contact battery 10 during soldering. Therefore, the third insulating member 6 can be configured as a split structure including two third connecting parts 61, that is, the third insulating member 6 is only used to insulate the end of the fine grid 3, and is not used to support the solder strip.

[0128] like Figure 2 As shown, two third connecting portions 61 respectively cover the ends of the broken sections of the fine grids 3 on both sides of the main grid 2 to ensure insulation between the main grid 2 and the fine grids 3 of opposite polarities. Simultaneously, the third connecting portions 61 also prevent the solder ribbon connected to the main grid 2 from contacting the ends of the broken sections of the fine grids 3 and forming an electrical connection with them. This reduces the risk of short circuits in the back contact cell 10 due to solder ribbon misalignment, which is beneficial for improving the structural reliability of the back contact cell 10 and also for improving the yield rate of the photovoltaic module.

[0129] In some embodiments, such as Figure 4 As shown, the third insulating member 6 also includes a third extension 62, which extends along the first direction X and is connected to the end of the third connecting part 61 away from the main grid 2. The third extension 62 covers the fine grid 3 and can also play a certain protective role for the fine grid 3, buffering the external impact force and reducing the risk of the fine grid 3 breaking.

[0130] Along the second direction Y, the width of the third connecting portion 61 can be greater than the width of the third extension portion 62, so as to improve the insulation effect of the third insulating member 6, appropriately save the raw materials of the third insulating member 6, reduce the manufacturing cost of the back contact battery 10, and also reduce the risk of the back contact battery 10 warping due to volume shrinkage of the third insulating member 6 during the curing process.

[0131] It should be noted that in the structure of the back contact battery 10 provided in this application, the insulating member used to insulate the main grid 2 and the fine grid 3 with opposite polarities can be only the first insulating member 4, or it can be a combination of at least one of the second insulating member 5 and the third insulating member 6 with the first insulating member 4.

[0132] In some embodiments, such as Figure 2As shown, the insulating component also includes a fourth insulating component 9. The fourth insulating component 9 is used to cover the ends of the fine grid 3 that are broken on both sides of the pad 7, so as to ensure the insulation effect between the pad 7 and the fine grid 3 of opposite polarity. At the same time, the fourth insulating component 9 can also prevent the solder ribbon connected to the pad 7 from contacting the end of the fine grid 3 and forming an electrical connection with the fine grid 3, thereby reducing the risk of short circuit of the back contact cell 10 caused by solder ribbon misalignment. This is beneficial to improving the structural reliability of the back contact cell 10 and also to improving the yield of photovoltaic modules.

[0133] In some embodiments, such as Figure 4 As shown, the fourth insulating member 9 may include two parts: a fourth connecting portion 91 and a fourth extending portion 92. The fourth connecting portion 91 is used to cover the ends of the fine gate 3 located on both sides of the pad 7 at the break points. The fourth extending portion 92 extends along the first direction X and is connected to the end of the fourth connecting portion 91 away from the pad 7. The fourth connecting portion 91 covers the fine gate 3, which can also play a certain protective role for the fine gate 3, buffering external impact forces and reducing the risk of breakage of the fine gate 3.

[0134] In some embodiments, the back contact cell 10 can be one of the following: interdigitated back contact (IBC), heterojunction back contact (HBC), or tunnel oxide back contact (TBC). 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 silver electrode. 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.

[0135] HBC cells effectively combine the advantages of IBC and heterojunction cells. Their front surface passivation layer uses hydrogenated amorphous silicon, while N-type and P-type amorphous silicon films are deposited on the back side to form a heterojunction. HBC cells fully utilize the superior surface passivation properties of amorphous silicon, and the heterojunction structure formed on the back side exhibits excellent passivation, enabling the simultaneous achievement of higher short-circuit current and open-circuit voltage, thereby improving photoelectric conversion efficiency.

[0136] For TBC cells, the advantages of both Topcon's tunneling oxide layer technology and IBC back-side electrode arrangement are combined, resulting in significantly improved passivation and open-circuit voltage, achieving higher cell conversion efficiency while maintaining economic viability. The complete TBC cell production process mainly includes depositing the tunneling oxide layer and P+ polycrystalline silicon, depositing the passivation film, and printing electrodes on the back of the silicon wafer. Building upon the TOPCon production process, TBC cells require additional back-side electrode processes such as masking, laser grooving, PN region fabrication, and etching. Masking is primarily performed using APCVD or PECVD, PN region fabrication is mainly done using PECVD, etching primarily employs traditional wet processing equipment, and grooving is performed using laser equipment.

[0137] This application also provides a back-contact stacked battery 20, such as Figure 8 As shown, the back-contact tandem solar cell 20 includes a back-contact bottom cell 201 and a perovskite top cell 202, with the perovskite top cell 202 electrically connected to the light-facing surface of the back-contact bottom cell 201. The back-contact bottom cell 201 can be the back-contact cell 10 described above. The perovskite top cell 202 is a thin-film solar cell with perovskite material as the photoactive layer. The structure of the perovskite top cell 202 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 cell 202 to effectively absorb sunlight and convert it into electrical energy. The perovskite material in the perovskite light-absorbing layer has excellent light absorption performance, absorbing a wider spectral range and effectively converting short-wavelength spectra, giving the perovskite top cell 202 high photoelectric conversion efficiency.

[0138] This application also provides a photovoltaic module, such as... Figure 9 and Figure 10 As shown, the photovoltaic module includes multiple photovoltaic cells and solder ribbons 30. The photovoltaic cells are either the back-contact cells 10 described above, or the back-contact tandem cells 20 described above. The main grids 2 of two adjacent photovoltaic cells along the second direction Y are connected by solder ribbons 30.

[0139] The photovoltaic module also includes a front panel 40, a front encapsulation layer 50, a back encapsulation layer 60, and a backsheet 70. The front panel 40 and the backsheet 70 together sandwich the front encapsulation layer 50, photovoltaic cells, solder ribbons 30, and back encapsulation layer 60, and form a photovoltaic module through lamination. The front encapsulation layer 50 protects the light-facing side of the photovoltaic cells, and the back encapsulation layer 60 protects the back-facing side of the photovoltaic cells. During the lamination process, the front encapsulation layer 50 and the back encapsulation layer 60 encapsulate and protect the photovoltaic cells and solder ribbons 30, preventing external environmental factors from affecting their performance. They also bond the front panel 40, backsheet 70, photovoltaic cells, and solder ribbons 30 into a single unit.

[0140] The front panel 40 and back panel 70 can be made of rigid materials such as tempered glass, polyethylene terephthalate (PET), and polycarbonate (PC), or flexible materials such as polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), and polyvinylidene fluoride (PVDF). The front encapsulation layer 50 and the back encapsulation layer 60 are adhesive films, which can be made of materials such as ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB). The front encapsulation layer 50 and the back encapsulation layer 60 can also be EPE film (EVA-POE-EVA co-extrusion structure) or EP film (EVA-POE co-extrusion structure).

[0141] 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, include: The body (1) has a backlight surface provided with a main grid (2) and a fine grid (3). The main grid (2) includes a first main grid (21) and a second main grid (22) that are alternately distributed along a first direction. The fine grid (3) includes a first fine grid (31) and a second fine grid (32) that are alternately distributed along a second direction. The first fine grid (31) and the second main grid (22) are spaced apart, and the second fine grid (32) and the first main grid (21) are spaced apart. The first insulating member (4) includes a first covering part (41) and a first connecting part (42) connected to each other. The first covering part (41) is provided with the first connecting part (42) on both sides along the first direction. At least a portion of the first covering portion (41) covers the main grid (2), and the two first connecting portions (42) respectively cover the ends of the fine grid (3) located on both sides of the main grid (2) and spaced apart from the main grid (2); Along the second direction, the width of the first covering part (41) is W1, and the width of the first connecting part (42) is W2. W1 and W2 satisfy: 1 ​​< W2: W1 ≤ 4; The first direction intersects with the second direction.

2. The back contact battery according to claim 1, characterized in that, The width W1 of the first covering part (41) is 0.2mm~0.6mm.

3. The back contact battery according to claim 1, characterized in that, Along the first direction, the length L1 of the first covering part (41) is 0.1mm~0.8mm.

4. The back contact battery according to claim 1, characterized in that, The first insulating member (4) further includes a first extension (43) that covers the fine grid (3); Along the first direction, the first extension (43) is connected to the end of the first connecting portion (42) away from the first covering portion (41).

5. The back contact battery according to claim 4, characterized in that, Along the second direction, the width W3 of the first extension (43) is less than or equal to the width W2 of the first connecting portion (42).

6. The back contact battery according to claim 1, characterized in that, The back contact battery (10) also includes a pad (7) and a second insulating element (5), the pad (7) being connected to the main grid (2); Along the second direction, the second insulating element (5) is located on the side of the first insulating element (4) near the pad (7); The second insulating member (5) includes a second connecting portion (51) and a protrusion (52) connected together. At least a portion of the second connecting portion (51) covers the main grid (2). Along the first direction, the two ends of the second connecting portion (51) respectively cover the ends of the fine grid (3) located on both sides of the main grid (2) and spaced apart from the main grid (2). The protrusion (52) extends along the second direction, and at least a portion of the protrusion (52) covers the fine gate (3) located between the pad (7) and the second insulating member (5) and connected to the main gate (2).

7. The back contact battery according to claim 6, characterized in that, Along the first direction, the width W4 of the protrusion (52) is 0.1mm~0.8mm.

8. The back contact battery according to claim 6, characterized in that, Along the second direction, the length L2 of the protrusion (52) is 0.1mm to 1.2mm.

9. The back contact battery according to claim 1, characterized in that, The back contact battery (10) also includes a pad (7) and a third insulating element (6), the pad (7) being connected to the main grid (2); Along the second direction, the third insulating member (6) is located on the side of the first insulating member (4) away from the pad (7); The third insulating element (6) includes two third connecting parts (61), which are respectively disposed on both sides of the main grid (2) along the first direction, and respectively cover the ends of the fine grid (3) which are spaced apart from the main grid (2).

10. A back-contact stacked battery, characterized in that, It includes a back contact bottom cell (201) and a perovskite top cell (202), wherein the perovskite top cell (202) is electrically connected to the light-facing surface of the back contact bottom cell (201); The back contact bottom battery (201) includes: The body (1) has a backlight surface provided with a main grid (2) and a fine grid (3). The main grid (2) includes a first main grid (21) and a second main grid (22) that are alternately distributed along a first direction. The fine grid (3) includes a first fine grid (31) and a second fine grid (32) that are alternately distributed along a second direction. The first fine grid (31) and the second main grid (22) are spaced apart, and the second fine grid (32) and the first main grid (21) are spaced apart. The first insulating member (4) includes a first covering part (41) and a first connecting part (42) connected to each other. The first covering part (41) is provided with the first connecting part (42) on both sides along the first direction. At least a portion of the first covering portion (41) covers the main grid (2), and the two first connecting portions (42) respectively cover the ends of the fine grid (3) located on both sides of the main grid (2) and spaced apart from the main grid (2); Along the second direction, the width of the first covering part (41) is W1, and the width of the first connecting part (42) is W2. W1 and W2 satisfy: 1 ​​< W2: W1 ≤ 4; The first direction intersects with the second direction.

11. A photovoltaic module, characterized in that, include: Multiple photovoltaic cells, wherein the photovoltaic cells are back-contact cells (10) as described in any one of claims 1-9, or the photovoltaic cells are back-contact stacked cells (20) as described in claim 10. The main grid (2) of two adjacent photovoltaic cells along the second direction is connected by the solder strip (30).

Images