A battery piece and a photovoltaic module

Abstract

The application relates to the technical field of solar cells, in particular to a cell piece and a photovoltaic module. The cell piece comprises a welding structure, a busbar fishhook and a busbar electrode. The welding structure comprises an edge welding structure located at the outermost side, the busbar fishhook is connected with the edge welding structure, and the busbar fishhook comprises a fishhook gap. The busbar electrode comprises a first electrode and a second electrode connected with the busbar fishhook, the first electrode is located between the second electrode and the edge welding structure, the first electrode penetrates through the fishhook gap along a second direction, and the second electrode is disconnected at the fishhook gap. The side of the first electrode located at the outermost side and away from the edge welding structure is an edge area of the cell piece, the arrangement spacing of at least part of the auxiliary busbar electrodes in the edge area is smaller than that of the auxiliary busbar electrodes in the remaining area, the number of the auxiliary busbar electrodes arranged in the edge area can be increased, the current collection efficiency can be improved, the electronic transmission path can be optimized, the brightness uniformity of EL test and the output power can be improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a solar cell and a photovoltaic module. Background Technology

[0002] The solar cell includes a main bus electrode and a secondary bus electrode, which extend orthogonally. A welding structure is provided on the main bus electrode for welding and fixing it to a welding strip, thereby achieving current collection and transmission. A bus harpoon is provided at the end of the main bus electrode, and a portion of the secondary bus electrode is electrically connected to the bus harpoon to collect current from that portion of the secondary bus electrode.

[0003] Normally, the secondary bus electrode connected to the busbar is disconnected at the busbar, which reduces the current collection efficiency of the solar cell and thus affects the efficiency of the solar cell.

[0004] Therefore, improving the current collection efficiency of solar cells is an important problem that needs to be solved in this field. Utility Model Content

[0005] In view of this, this application provides a solar cell and a photovoltaic module that can optimize the current collection path of the solar cell.

[0006] This application provides a battery cell, including a substrate and welding structures, a busbar, and bus electrodes disposed on the substrate. Multiple welding structures are arranged along a first direction, including an outermost edge welding structure in the first direction and a central welding structure, wherein the central welding structure is located on one side of the edge welding structures in the first direction. The busbar is located on the side of the edge welding structures opposite to the central welding structure, and includes a busbar gap. The bus electrodes include at least a sub-busbar electrode extending along a second direction, comprising a first electrode and a second electrode, both located on the side of the edge welding structures opposite to the central welding structure in the first direction, with the first electrode located between the second electrode and the edge welding structures. Both the first and second electrodes are connected to the busbar, with the first electrode extending through the busbar gap in the second direction and the second electrode disconnected at the busbar gap. The battery cell includes an edge region, located on the side of the outermost first electrode opposite to the edge welding structure in the first direction, wherein the spacing between at least a portion of the sub-busbar electrodes in the edge region is smaller than the spacing between the sub-busbar electrodes in the remaining regions in the first direction.

[0007] In this application, the first electrode passes through the busbar harpoon, meaning that the first electrode is not disconnected at the busbar harpoon, which optimizes the current collection path, helps reduce current transmission loss, and thus improves the output power of the solar cell.

[0008] The second electrode is disconnected at the harpoon junction, which reduces the amount of paste required for the second electrode, thereby reducing the material cost of the second electrode and thus helping to reduce the cost of the solar cell. At the same time, it reduces the risk of grid breakage of the second electrode during the welding process and optimizes the electron transport path, which helps to improve the output power of the solar cell.

[0009] The spacing between the secondary bus electrodes in the edge region is smaller than that in other regions. This increases the number of secondary bus electrodes in the edge region, thereby reducing the risk of reduced collection efficiency caused by the secondary bus electrodes in the edge region being interrupted by the bus harpoon. This helps to improve the current collection efficiency of the solar cell and also helps to optimize the electron transport path of the solar cell, thereby improving the brightness uniformity of the solar cell EL test and the output power of the solar cell.

[0010] In some possible designs, the number of second electrodes arranged in the first direction within the edge region is one. In the first direction, the spacing between adjacent first electrodes is L1, and the spacing between the second electrode and its adjacent first electrode is L2, where L2 < L1.

[0011] In some possible designs, the number of second electrodes arranged in the first direction within the edge region is at least two. In the first direction, the spacing between adjacent first electrodes is L1, the spacing between the outermost first electrode and its adjacent second electrode is L2, the spacing between adjacent second electrodes is L3, L2 < L1, and / or, L3 < L1.

[0012] In some possible designs, the number of second electrodes arranged in the first direction in the edge region is N1, where 1≤N1≤10.

[0013] In some possible designs, the substrate includes a first edge and a second edge arranged along a first direction. The edge welding structure includes a first edge welding structure and a second edge welding structure arranged along the first direction, with the first edge welding structure located between the first edge and the second edge welding structure in the first direction. In the first direction, a busbar is disposed between the first edge welding structure and the first edge, and between the second edge welding structure and the second edge. In the first direction, a first electrode and a second electrode are located between the first edge welding structure and the first edge. The sub-busbar electrode also includes a third electrode, located between the second edge welding structure and the second edge in the first direction. The third electrode is connected to the busbar and extends through the gap in the busbar along the second direction. Multiple third electrodes are arranged along the first direction, and in the first direction, the solar cell includes an outermost edge electrode, with the third electrode configured as an edge electrode.

[0014] In some possible designs, the first, second, and third electrodes are located on the same side of the substrate along the thickness direction of the solar cell. Alternatively, the first and second electrodes are located on one side of the substrate, and the third electrode is located on the other side of the substrate, along the thickness direction of the solar cell.

[0015] In some possible designs, in a first direction, the solar cell includes an outer electrode located on the outside and an inner electrode located on the inside, with the outer electrode situated on either side of the inner electrode. In the first direction, the width of the outer electrode is greater than the width of the inner electrode.

[0016] In some possible designs, the width of the outer electrode is H1 in the first direction, where 10 μm ≤ H1 ≤ 30 μm.

[0017] In some possible designs, in the first direction, the number of outer electrodes on the side of the inner electrode is N2, where 1≤N2≤10.

[0018] In some possible designs, the central welding structure includes main welding structures and sub-welded structures. Multiple main welding structures are arranged along a first direction, and at least two sub-welded structures are between two adjacent main welding structures. In the thickness direction of the solar cell, the projected area of ​​the main welding structure is larger than the projected area of ​​the sub-welded structure.

[0019] In some possible designs, in the first direction, there are at least three secondary welded structures between the edge welded structure and the adjacent main welded structure.

[0020] In some possible designs, in the second direction, the width of the main welded structure is W1, the width of the secondary welded structure is W2, W2 < W1, 1mm ≤ W1 ≤ 3.5mm, and 0.3mm ≤ W2 ≤ 1.2mm.

[0021] In some possible designs, the outline of the main welded structure is circular or rectangular. The outline of the secondary welded structure is T-shaped, I-shaped, or Z-shaped.

[0022] In some possible designs, the number of secondary bus electrodes between two adjacent welded structures is zero in the first direction, or at least one secondary bus electrode is included between two adjacent welded structures. The welded structures and secondary bus electrodes are arranged periodically in the first direction.

[0023] In some possible designs, in the first direction, the number of sub-bus electrodes between two adjacent welding structures is 0. The middle welding structure includes a main welding structure and a sub-welding structure. In the thickness direction of the cell, the projected area of the main welding structure is larger than that of the sub-welding structure. The sub-bus electrode includes a main welding electrode and a sub-welding electrode. The end of the main welding electrode contacts the main welding structure, and the end of the sub-welding electrode contacts the sub-welding structure. In the first direction, the distance between the main welding electrode and the adjacent sub-welding electrode is H2, and the distance between two adjacent sub-welding electrodes is H3, where 0.3 ≤ H2 / H3 ≤ 7.

[0024] In some possible designs, 0.5 mm ≤ H2 ≤ 2 mm, 0.3 mm ≤ H3 ≤ 1.5 mm, and H3 < H2.

[0025] In some possible designs, the cell has no main bus electrode, and the welding structure is directly connected to the sub-bus electrode.

[0026] In some possible designs, the cell further includes a main bus electrode extending in the first direction. The sub-bus electrode is connected to the main bus electrode, and at least part of the welding structure is located on the main bus electrode. Multiple main bus electrodes are arranged at intervals in the second direction, and the number of main bus electrodes in the second direction is N3, where 5 ≤ N3 ≤ 24.

[0027] In some possible designs, the cell further includes a main bus electrode extending in the first direction. The sub-bus electrode is connected to the main bus electrode, and at least part of the welding structure is located on the main bus electrode. Multiple main bus electrodes are arranged at intervals in the second direction. The welding structures arranged in the first direction form a welding row, and multiple welding rows are arranged in the second direction. In the second direction, the number of main bus electrodes is the same as the number of welding rows, or, in the second direction, the number of main bus electrodes is less than the number of welding rows, and at least one welding row is included between two adjacent main bus electrodes.

[0028] The second party of the present application provides a photovoltaic module, including a packaging board, a packaging layer, and a cell layer. The cell layer includes multiple cells as described in any one of the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of the cell provided by the present application in some embodiments;

[0031] Figure 2 The diagram shows the structure of the battery cell provided in this application in some embodiments.

[0032] Figure 3 The diagram shows the structure of the battery cell provided in this application in some embodiments.

[0033] Figure 4 This is a partial structural diagram of the battery cell in some embodiments;

[0034] Figure 5 This is a partial structural diagram of the battery cell in some other embodiments;

[0035] Figure 6 for Figure 5 Enlarged view of part A in some embodiments;

[0036] Figure 7 for Figure 5 Enlarged view of part A in some other embodiments;

[0037] Figure 8 for Figure 5 Enlarged structural view of part A in some embodiments;

[0038] Figure 9 for Figure 5 Enlarged structural view of part A in some embodiments;

[0039] Figure 10 for Figure 5 Enlarged structural view of part A in some embodiments;

[0040] Figure 11 for Figure 5 Enlarged structural view of part A in some embodiments;

[0041] Figure 12 for Figure 5 Enlarged view of part B in some embodiments;

[0042] Figure 13 for Figure 5 A schematic diagram of a partial structure of the first surface of the battery cell in some embodiments;

[0043] Figure 14 for Figure 13 A partial structural diagram of the second surface of the solar cell;

[0044] Figure 15 for Figure 5 A partial structural diagram of the first surface of the battery cell in some other embodiments;

[0045] Figure 16 for Figure 5 Enlarged structural view of part A in some embodiments;

[0046] Figure 17 for Figure 5 Enlarged structural view of part A in some embodiments;

[0047] Figure 18 for Figure 5 Enlarged view of part C in some embodiments;

[0048] Figure 19 for Figure 5 Enlarged view of part C in some other embodiments;

[0049] Figure 20 for Figure 5 Enlarged view of part C in some other embodiments;

[0050] Figure 21 for Figure 5 Enlarged view of part D in some embodiments;

[0051] Figure 22 This is a partial structural diagram of the battery cell in some other embodiments;

[0052] Figure 23 for Figure 22 Enlarged view of part E in some embodiments;

[0053] Figure 24 for Figure 22 Enlarged view of part E in some other embodiments;

[0054] Figure 25 This is a partial structural diagram of the battery cell in some other embodiments;

[0055] Figure 26 This is a partial structural diagram of the battery cell in some other embodiments;

[0056] Figure 27 for Figure 26 Enlarged view of the structure of part F in some embodiments;

[0057] Figure 28 This application provides a schematic diagram of the structure of a photovoltaic module in some embodiments.

[0058] Figure 29 for Figure 28 A schematic diagram of the connection structure of the battery layer in some embodiments;

[0059] Figure 30 for Figure 28 The diagram shows the structure of the battery layer in some embodiments.

[0060] Figure label:

[0061] 100 - Package board; 110 - First package board; 120 - Second package board;

[0062] 200 - Encapsulation layer; 210 - First encapsulating film; 220 - Second encapsulating film;

[0063] 300 - Battery layer; 310 - Battery cell; 311 - Full cell; 312 - Two-cell cell; 313 - Three-cell cell; 320 - Welding strip; 330 - Busbar;

[0064] 340 - Substrate; 341 - First edge; 342 - Second edge; 343 - Edge region; 344 - First surface; 345 - Second surface;

[0065] 350 - Welded structure; 351 - Edge welded structure; 3511 - First edge welded structure; 3512 - Second edge welded structure; 352 - Middle welded structure; 3521 - Main welded structure; 3522 - Secondary welded structure; 353 - Welded row;

[0066] 360 - Harpoon junction; 361 - First harpoon section; 362 - Second harpoon section; 363 - Harpoon gap;

[0067] 370 - Secondary bus electrode; 371 - First electrode; 372 - Second electrode; 3721 - First electrode section; 3722 - Second electrode section; 373 - Third electrode; 374 - Outer electrode; 375 - Inner electrode; 376 - Main welding electrode; 377 - Secondary welding electrode;

[0068] 380 - Main bus electrode; X - Second direction; Y - First direction; Z - Third direction. Detailed Implementation

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] The first aspect of this application provides a battery cell, the types of which include, but are not limited to, passivated emitter rear cell (PERC), tunnel oxide passivated contact (TOPCon), intrinsic thin-film heterojunction (HJT), interdigitated back contact (IBC), perovskite battery, etc.

[0074] For PERC cells, along their thickness direction, the PERC cell sequentially includes a front-surface silver electrode, a front-surface silicon nitride passivation layer, a phosphorus emitter layer, a P-type substrate silicon layer, a localized aluminum back field, a metallic aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back side, replacing the all-aluminum back field, enhancing light reflection within the silicon substrate, reducing the recombination rate on the back side, and improving the cell efficiency by 0.5%-1%.

[0075] For a TOPCon cell, along its thickness direction, it sequentially comprises a silver electrode, a front-surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffused doped layer, an ultrathin silicon oxide layer, doped polycrystalline silicon, silicon nitride, and the silver electrode. The back of the cell consists of an ultrathin silicon oxide layer (1nm–2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure blocks minority carrier recombination, increasing the cell's open-circuit voltage and short-circuit current. The ultrathin oxide layer allows majority carrier electrons to tunnel into the polycrystalline silicon layer while simultaneously blocking minority carrier recombination. The excellent passivation effect of the ultrathin silicon oxide and heavily doped silicon film causes band bending on the silicon wafer surface, creating a field passivation effect. This significantly increases the probability of electron tunneling, reduces contact resistance, and improves the cell's open-circuit voltage and short-circuit current, thereby enhancing the cell's conversion efficiency.

[0076] For an HJT cell, along its thickness direction, the HJT cell sequentially includes a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type substrate silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0077] For an IBC cell, along its thickness direction, it 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 precisely controllable junction depth. The absence of grid lines on the front side eliminates light-blocking current loss from the metal electrodes, maximizing the utilization of incident photons and improving short-circuit current by approximately 7% compared to conventional solar cells. Due to its 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 reflection.

[0078] For a perovskite solar cell, along its thickness direction, it sequentially comprises a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials possess a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrodes with minimal loss, thus generating high photogenerated voltage and current, resulting in high photoelectric conversion efficiency.

[0079] The following discussion uses TOPCon batteries as an example to illustrate the specific structure of battery cells.

[0080] Figure 1 The diagram shows the structure of the battery cell provided in this application in some embodiments. Figure 1 As shown, in some embodiments, the battery cell is a whole battery 311. In this case, the first edge 341 and the second edge 342 of the battery cell are both uncut edges, and chamfers are provided at both the first edge 341 and the second edge 342.

[0081] Figure 2 The diagram shows the structure of the battery cell provided in this application in some embodiments. Figure 2 As shown, in some other embodiments, the battery cell is a two-piece battery 312, that is, the entire battery cell 311 is arranged along... Figure 2 The dotted line in the middle is cut into two halves. One half is taken to make a two-piece battery 312. At this time, one of the first edge 341 and the second edge 342 of the battery piece is a non-cut edge and the other is a cut edge. The non-cut edge is chamfered, while the cut edge is not chamfered.

[0082] Figure 3 The diagram shows the structure of the battery cell provided in this application in some embodiments. Figure 3As shown, in some other embodiments, the battery cell is a three-cell battery 313 or other multi-cell battery. Taking a three-cell battery 313 as an example, the entire battery cell 311 is arranged along... Figure 3 The battery is cut into three pieces by the dotted lines in the diagram, and one of these pieces is used to make a three-piece battery 313. In this case, one of the first edge 341 and the second edge 342 of the battery piece is a non-cut edge and the other is a cut edge. The non-cut edge has a chamfer, while the cut edge does not. Alternatively, both the first edge 341 and the second edge 342 are cut edges, and neither the first edge 341 nor the second edge 342 has a chamfer.

[0083] The embodiments of this application do not specifically limit the type of battery cell, that is, the battery cell can be a whole cell 311, a two-cell cell 312, a three-cell cell 313, or other multi-cell cells.

[0084] Figure 4 This is a partial structural diagram of a battery cell in some embodiments. Figure 4 The example shows a whole cell 311, where the first edge 341 and the second edge 342 of the cell are both uncut edges.

[0085] Figure 5 This is a partial structural diagram of the battery cell in some other embodiments. Figure 5 The example shows a two-piece battery 312, with the first edge 341 being a cut edge and the second edge 342 being an uncut edge.

[0086] The following discussion uses the 312 bi-cell battery as an example to illustrate the specific structure of the battery cell.

[0087] like Figure 5 As shown, the battery cell includes a substrate 340, which includes a light-facing surface and a back-lighting surface arranged along its thickness direction. The light-facing surface is the side of the substrate 340 facing the sunlight when the back-contact battery is in operation, and the back-lighting surface is the side of the substrate 340 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 substrate 340, and the back-lighting surface can be understood as the lower surface of the substrate 340.

[0088] like Figure 5 As shown, both the light-facing surface and the back-light-facing surface of the substrate 340 are provided with sub-current collector electrodes 370 extending along the second direction X. Multiple sub-current collector electrodes 370 are arranged along the first direction Y, and the polarity of the sub-current collector electrodes 370 on the light-facing surface is opposite to that on the back-light-facing surface. For example, the sub-current collector electrodes 370 on the light-facing surface are positive electrodes, and the sub-current collector electrodes 370 on the back-light-facing surface are negative electrodes.

[0089] Wherein, the first direction Y and the second direction X are both perpendicular to the thickness direction of the substrate 340. For example, one of the first direction Y and the second direction X is the length direction of the substrate 340 and the other is the width direction of the substrate 340. The thickness direction of the substrate 340 is denoted as the third direction Z. Then the first direction Y, the second direction X and the third direction Z are perpendicular to each other.

[0090] like Figure 5 As shown, the substrate 340 is also provided with a welding structure 350, which is used to weld and fix the substrate to the welding strip. The welding strip is used to realize the electrical connection between adjacent solar cells and to output the current from the solar cells. The welding structure 350 is also used to electrically connect to the secondary bus electrode 370. The current on the secondary bus electrode 370 can be transmitted to the welding strip through the welding structure 350, thereby realizing the collection and transmission of current on the solar cells.

[0091] like Figure 5 As shown, multiple welding structures 350 are arranged along the first direction Y, that is, a welding strip is welded and fixed to the solar cell through multiple welding structures 350, so as to improve the pull-out force between the welding strip and the solar cell, reduce the risk of the output power of the solar cell being reduced or even zero due to the separation of the welding strip and the solar cell, thereby improving the performance of the solar cell.

[0092] When the battery cell has a main bus electrode extending along the first direction Y, the welding structure is disposed on the main bus electrode, and the secondary bus electrode is electrically connected to the main bus electrode, that is, the secondary bus electrode and the welding structure are indirectly electrically connected through the main bus electrode.

[0093] Furthermore, when the solar cell has a main bus electrode, the secondary bus electrode can also be directly electrically connected to the welded structure.

[0094] The solar cell may also exclude the main bus electrode. In this case, the welding structure is set on the secondary bus electrode, that is, there is a direct electrical connection between the secondary bus electrode and the welding structure.

[0095] The embodiments of this application do not specifically limit the type of battery cell. For ease of description, the specific structure of the battery cell will be discussed in detail below with the example of a battery cell having a main bus electrode.

[0096] like Figure 5 As shown, the substrate 340 also includes a first edge 341 and a second edge 342 distributed along the first direction Y.

[0097] like Figure 5As shown, multiple welding structures 350 are arranged along the first direction Y. The welding structure 350 located on the outermost side in the first direction Y is referred to as the edge welding structure 351. The edge welding structure 351 includes a first edge welding structure 3511 and a second edge welding structure 3512 located on both sides of the battery cell in the first direction Y. The first edge welding structure 3511 is located on the side where the first edge 341 is located, and the second edge welding structure 3512 is located on the side where the second edge 342 is located.

[0098] In the first direction Y, the welding structure 350 located between the first edge welding structure 3511 and the second edge welding structure 3512 is referred to as the middle welding structure 352, that is, in the first direction Y, the middle welding structure 352 is located on one side of the edge welding structure 351.

[0099] like Figure 5 As shown, a converging harpoon 360 is provided on at least one of the light-facing surface and the backlight surface, and in the first direction Y, the converging harpoon 360 is located on the side of the edge welding structure 351 away from the middle welding structure 352.

[0100] Figure 6 for Figure 5 The enlarged structural view of part A in some embodiments is shown. For example... Figure 6 As shown, the harpoon 360 includes a first harpoon section 361 and a second harpoon section 362. Both the first harpoon section 361 and the second harpoon section 362 are connected to the edge welding structure 351. The first harpoon section 361 and the second harpoon section 362 have a harpoon gap 363 in the second direction X.

[0101] The extension direction of the first busbar 361 can be parallel to the first direction Y, or it can have an angle greater than 0 and less than 90° with the first direction Y. This application embodiment does not impose any special limitation on the extension direction of the first busbar 361.

[0102] The extension direction of the second busbar 362 can be parallel to the first direction Y, or there can be an angle greater than 0 and less than 90° between it and the first direction Y. This application embodiment does not impose any special limitation on the extension direction of the second busbar 362.

[0103] The first busbar 361 and the second busbar 362 can be symmetrically arranged on both sides of the edge welding structure 351, or they can be arranged asymmetrically. The present application embodiment does not impose any special limitation on the distribution of the first busbar 361 and the second busbar 362.

[0104] The first busbar 361 and the second busbar 362 can be symmetrically arranged on both sides of the edge welding structure 351, or they can be arranged asymmetrically. The present application embodiment does not impose any special limitation on the distribution of the first busbar 361 and the second busbar 362.

[0105] like Figure 6 As shown, the secondary bus electrode 370 includes a first electrode 371 and a second electrode 372. In the first direction Y, both the first electrode 371 and the second electrode 372 are located on the side of the edge welding structure 351 away from the central welding structure 352, with the first electrode 371 located between the second electrode 372 and the edge welding structure 351. Taking the side where the first edge 341 is located as an example, both the first electrode 371 and the second electrode 372 are located between the first edge welding structure 3511 and the first edge 341, with the first electrode 371 located between the second electrode 372 and the first edge welding structure 3511.

[0106] like Figure 6 As shown, the first electrode 371 and the second electrode 372 are both connected to the harpoon 360. The first electrode 371 passes through the harpoon gap 363 along the second direction X, and the second electrode 372 is disconnected at the harpoon gap 363 to form a first electrode portion 3721 and a second electrode portion 3722 distributed along the second direction X.

[0107] In this embodiment, the current on the first electrode 371 and the second electrode 372 can be transmitted to the edge welding structure 351 through the first busbar 361 and the second busbar 362, and then transmitted to the welding strip through the edge welding structure 351, so as to realize the collection and transmission of the current on the first electrode 371 and the second electrode 372, improve the current collection efficiency at the edge of the cell, and thus improve the output power of the cell.

[0108] The second electrode 372 is disconnected at the harpoon 360, which reduces the amount of paste required for the second electrode 372, thereby reducing the material cost of the second electrode 372 and thus helping to reduce the cost of the solar cell. At the same time, it reduces the risk of grid breakage of the second electrode 372 during the welding process and optimizes the electron transport path, thereby helping to improve the output power of the solar cell.

[0109] The first electrode 371 penetrates the busbar 360, meaning that the first electrode 371 is not disconnected at the busbar 360. This optimizes the current collection path, helps reduce current transmission loss, and thus improves the output power of the solar cell.

[0110] In some embodiments, such as Figure 6 As shown, the end of the first electrode portion 3721 facing the second electrode portion 3722 is connected to the first busbar portion 361, and the end of the second electrode portion 3722 facing the first electrode portion 3721 is connected to the second busbar portion 362, so as to reduce the length of the second electrode 372 and thereby reduce the material cost of the second electrode 372.

[0111] Figure 7 for Figure 5The enlarged structural view of part A in some embodiments. In other embodiments, such as Figure 7 As shown, the first electrode portion 3721 is connected to the first busbar portion 361, and the first electrode portion 3721 extends along the second direction X into the harpoon gap 363. The second electrode portion 3722 is connected to the second busbar portion 362, and the second electrode portion 3722 extends along the second direction X into the harpoon gap 363, so as to increase the length of the second electrode 372 and improve the current collection efficiency of the second electrode 372.

[0112] Refer again Figure 6 The battery cell includes an edge region 343. In the first direction Y, the edge region 343 is located on the side of the outermost first electrode 371371 away from the edge welding structure 351. In the first direction Y, the spacing of at least a portion of the sub-bus electrodes 370 in the edge region 343 is smaller than the spacing of the sub-bus electrodes 370 in the remaining regions.

[0113] In this embodiment, the spacing between the secondary bus electrodes 370 in the edge region 343 is smaller than that in the other regions. This increases the number of secondary bus electrodes 370 in the edge region 343, thereby reducing the risk of reduced collection efficiency caused by the secondary bus electrodes 370 in the edge region 343 being interrupted by the bus harpoon 360. This is to improve the current collection efficiency of the solar cell and also to optimize the electron transport path of the solar cell, thereby improving the brightness uniformity and output power of the solar cell in the EL test.

[0114] Within the edge region 343, the number of second electrodes 372 can be one or more.

[0115] Within the edge region 343, the number of second electrodes 372 arranged in the first direction Y is N1, where 1≤N1≤10. For example, the number of second electrodes 372 arranged in the first direction Y can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0116] In some embodiments, the structure of the battery cell is as follows: Figure 6 As shown, within the edge region 343, the number of second electrodes 372 arranged in the first direction Y is one. In the first direction Y, the distance between adjacent first electrodes 371 is L1, and the distance between the second electrode 372 and its adjacent first electrode 371 is L2, where L2 < L1.

[0117] In this embodiment, there is only one second electrode 372, which reduces the number of interrupted second electrodes 372. By reducing the distance between the second electrode 372 and the adjacent first electrode 371, the electron transport path in the edge region 343 is optimized, thereby improving the brightness uniformity of the cell EL test and the output power of the cell.

[0118] In some embodiments, the structure of the battery cell is as follows: Figure 8 As shown, within the edge region 343, the number of second electrodes 372 arranged in the first direction Y is at least two. In the first direction Y, the spacing between adjacent first electrodes 371 is L1, the spacing between the outermost first electrode 371 and its adjacent second electrode 372 is L2, and the spacing between adjacent second electrodes 372 is L3. L2 < L1, and / or, L3 < L1, meaning at least one of L2 and L3 is less than L1. For example, as... Figure 6 and 8 As shown, L2 < L1, and L3 = L1. Alternatively, for example, as... Figure 9 As shown, L2 = L1, and L3 < L1. Alternatively, for example, as... Figure 10 As shown, L2 < L1, and the spacing between some adjacent second electrodes 372 is less than L1, while the spacing between other adjacent second electrodes 372 is equal to L1. Alternatively, as exemplarily, such as... Figure 11 As shown, L2 < L1, and the spacing between all adjacent second electrodes 372 is less than L1.

[0119] In this embodiment, by setting multiple interrupted second electrodes 372, the number of uninterrupted first electrodes 371 can be reduced, thereby lowering the material cost of the secondary bus electrode 370. By setting multiple second electrodes 372 and reducing the spacing between adjacent second electrodes 372 and the spacing between a second electrode 372 and an adjacent first electrode 371, the number of second electrodes 372 can be increased, and the electron transport path in the edge region 343 can be optimized, thereby improving the brightness uniformity of the solar cell EL test and the output power of the solar cell.

[0120] For example, 0.8mm≤L1≤1.2mm, the spacing between adjacent first electrodes 371 can be 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, etc.

[0121] If the spacing between adjacent first electrodes 371 is large, the number of first electrodes 371 will be small, the current transmission efficiency of the first electrodes 371 will be low, and there is a greater risk of low output power of the solar cell.

[0122] If the spacing between adjacent first electrodes 371 is small, the number of first electrodes 371 will be large, the cost will be high, and the first electrodes 371 will block a large area of ​​the substrate 340, affecting the photoelectric conversion efficiency of the solar cell and increasing the risk of low output power of the solar cell.

[0123] Therefore, 0.8mm≤L1≤1.2mm can improve the photoelectric conversion efficiency and current transmission efficiency of the solar cell, thereby increasing the output power of the solar cell and helping to reduce the cost of the solar cell.

[0124] For example, 0.8mm≤L1≤0.9mm, the spacing between adjacent first electrodes 371 can be 0.8mm, 0.81mm, 0.82mm, 0.83mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.89mm, 0.9mm, etc.

[0125] For example, 0.9mm≤L1≤1mm, the spacing between adjacent first electrodes 371 can be 0.9mm, 0.91mm, 0.92mm, 0.93mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 0.99mm, 1mm, etc.

[0126] For example, 1mm≤L1≤1.1mm, the spacing between adjacent first electrodes 371 can be 1mm, 1.01mm, 1.02mm, 1.03mm, 1.04mm, 1.05mm, 1.06mm, 1.07mm, 1.08mm, 1.09mm, 1.1mm, etc.

[0127] For example, 1.1mm≤L1≤1.2mm, the spacing between adjacent first electrodes 371 can be 1.1mm, 1.11mm, 1.12mm, 1.13mm, 1.14mm, 1.15mm, 1.16mm, 1.17mm, 1.18mm, 1.19mm, 1.2mm, etc.

[0128] refer to Figure 8 and Figure 10 When L2 < L1, 0.3mm ≤ L2 ≤ 0.8mm. For example, L2 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, etc.

[0129] If L2 is small, the distance between the second electrode 372 and the adjacent first electrode 371 is small, which increases the printing difficulty and printing cost of the first electrode 371 and the second electrode 372.

[0130] If L2 is large, the distance between the second electrode 372 and the adjacent first electrode 371 will be large, resulting in a poor improvement effect on the electron collection path of the edge region 343.

[0131] Therefore, 0.3mm≤L2≤0.8mm can optimize the electron collection path of the edge region 343, improve the output power of the cell, and also help reduce the printing difficulty and printing cost of the first electrode 371 and the second electrode 372, so as to reduce the cost of the cell.

[0132] For example, 0.3mm≤L2≤0.5mm, where L2 can be 0.3mm, 0.31mm, 0.33mm, 0.35mm, 0.37mm, 0.39mm, 0.4mm, 0.41mm, 0.43mm, 0.45mm, 0.47mm, 0.49mm, 0.5mm, etc.

[0133] For example, 0.5mm≤L2≤0.7mm, where L2 can be 0.5mm, 0.51mm, 0.53mm, 0.55mm, 0.57mm, 0.59mm, 0.6mm, 0.61mm, 0.63mm, 0.65mm, 0.67mm, 0.69mm, 0.7mm, etc.

[0134] For example, 0.7mm≤L2≤0.8mm, where L2 can be 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm, 0.8mm, etc.

[0135] refer to Figure 9 and Figure 10 When L3 < L1, 0.3mm ≤ L3 ≤ 0.8mm. For example, L3 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, etc.

[0136] If L3 is small, the distance between adjacent second electrodes 372 is small, which increases the printing difficulty and printing cost of the second electrodes 372.

[0137] If L3 is large, the distance between adjacent second electrodes 372 is large, resulting in a poor improvement effect on the electron collection path of the edge region 343.

[0138] Therefore, 0.3mm≤L3≤0.8mm can optimize the electron collection path of the edge region 343, improve the output power of the cell, and also help reduce the printing difficulty and printing cost of the second electrode 372, thereby reducing the cost of the cell.

[0139] For example, 0.3mm≤L3≤0.5mm, where L3 can be 0.3mm, 0.31mm, 0.33mm, 0.35mm, 0.37mm, 0.39mm, 0.4mm, 0.41mm, 0.43mm, 0.45mm, 0.47mm, 0.49mm, 0.5mm, etc.

[0140] For example, 0.5mm≤L3≤0.7mm, where L3 can be 0.5mm, 0.51mm, 0.53mm, 0.55mm, 0.57mm, 0.59mm, 0.6mm, 0.61mm, 0.63mm, 0.65mm, 0.67mm, 0.69mm, 0.7mm, etc.

[0141] For example, 0.7mm≤L3≤0.8mm, where L3 can be 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm, 0.8mm, etc.

[0142] In some embodiments, the sub-bus electrode 370 between the first edge welding structure 3511 and the first edge 341, and between the second edge welding structure 3512 and the second edge 342, has the same structure. That is, the aforementioned busbar 360, the first electrode 371, and the second electrode 372 are provided between the first edge welding structure 3511 and the first edge 341, and between the second edge welding structure 3512 and the second edge 342.

[0143] In other embodiments, the structures of the secondary bus electrodes 370 between the first edge welding structure 3511 and the first edge 341, and between the second edge welding structure 3512 and the second edge 342, are different. The first electrode 371 and the second electrode 372 are located between the first edge welding structure 3511 and the first edge 341. Figure 12 for Figure 5 Enlarged structural views of part B in some embodiments, such as Figure 12 As shown, the secondary bus electrode 370 also includes a third electrode 373. In the first direction Y, the third electrode 373 is located between the second edge welding structure 3512 and the second edge 342. The third electrode 373 is connected to the bus harpoon 360, and the third electrode 373 passes through the harpoon gap 363 in the second direction X.

[0144] like Figure 12 As shown, a plurality of third electrodes 373 are arranged along the first direction Y. In the first direction Y, the cell includes an outermost edge electrode. The third electrode 373 is configured as an edge electrode, that is, between the second edge welding structure 3512 and the second edge 342, to the third electrode 373 provided with a through-hole gap 363.

[0145] In this embodiment, the third electrode 373 penetrates the busbar 360, meaning that the third electrode 373 is not disconnected at the busbar 360. This improves the current collection efficiency on the side where the second edge 342 of the solar cell is located, optimizes the current collection path, helps reduce current transmission loss, and thus improves the brightness uniformity of the solar cell EL test and the output power of the solar cell.

[0146] The first electrode 371, the second electrode 372, and the third electrode 373 can be located on the same side surface of the substrate 340, or they can be located on different sides of the substrate 340.

[0147] Based on the aforementioned sub-bus electrode 370 structure, on the light-facing surface of the substrate 340, the sub-bus electrode 370 structure at the first edge 341 and the sub-bus electrode 370 structure at the second edge 342 can be the same or different. On the backlight surface of the substrate 340, the sub-bus electrode 370 structure at the first edge 341 and the sub-bus electrode 370 structure at the second edge 342 can be the same or different. The sub-bus electrode 370 structure on the light-facing surface of the substrate 340 and the sub-bus electrode 370 structure on the backlight surface can be the same or different.

[0148] Figure 13 for Figure 5 A partial structural diagram of the first surface 344 of the battery cell in some embodiments is shown. (See attached diagram.) Figure 13 As shown, on the first surface 344 of the substrate 340, the sub-bus electrode 370 structure at the first edge 341 is the same as the sub-bus electrode 370 structure at the second edge 342. That is, the first electrode 371 and the second electrode 372 are both present between the first edge 341 and the first edge welding structure 3511, and between the second edge 342 and the second edge welding structure 3512.

[0149] Figure 14 for Figure 13 A partial structural diagram of the second surface 345 of the solar cell. (See diagram below.) Figure 14 As shown, on the second surface 345 of the substrate 340, the sub-bus electrode 370 structure at the first edge 341 is the same as the sub-bus electrode 370 structure at the second edge 342, that is, the aforementioned third electrode 373 is present between the first edge 341 and the first edge welding structure 3511, and between the second edge 342 and the second edge welding structure 3512.

[0150] Also refer to Figure 13 and Figure 14 In the thickness direction of the battery cell, the first electrode 371 and the second electrode 372 are located on one side of the substrate 340, and the third electrode 373 is located on the other side of the substrate 340.

[0151] Figure 15 for Figure 5 A partial structural diagram of the first surface 344 of the battery cell in some other embodiments. For example... Figure 15 As shown, the structure of the secondary bus electrode 370 at the first edge 341 is different from that at the second edge 342. That is, the first edge 341 and the first edge welding structure 3511 have the aforementioned first electrode 371 and second electrode 372, and the second edge 342 and the second edge welding structure 3512 have the aforementioned third electrode 373.

[0152] like Figure 15 As shown, in the thickness direction of the battery cell, the first electrode 371, the second electrode 372, and the third electrode 373 are located on the same side of the substrate 340.

[0153] Based on the above-described sub-current collector electrode 370 structure, the current collection efficiency at the edge of the cell can be improved by adjusting the width of the sub-current collector electrode 370. The following discussion will take the sub-current collector electrode 370 structure at the first edge 341 as an example.

[0154] Figure 16 for Figure 5 The enlarged structural view of part A in some embodiments is shown. For example... Figure 16 As shown, in the first direction Y, the battery cell includes an outer electrode 374 located on the outside and an inner electrode 375 located on the inside. In the first direction Y, the outer electrode 374 is located on both sides of the inner electrode 375. In the first direction Y, the width of the outer electrode 374 is greater than the width of the inner electrode 375.

[0155] In this embodiment, the width of the outer electrode 374 is greater than the width of the inner electrode 375, which improves the current collection efficiency at the edge of the cell, helps to improve the brightness uniformity of the cell EL test, reduces the risk of local failure after cell aging, and thus improves the output power of the cell.

[0156] For example, in the first direction Y, the width of the outer electrode 374 is H1, 10μm≤H1≤30μm, and the width of the outer electrode 374 can be 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, etc.

[0157] If the width of the outer electrode 374 is large, the material cost of the outer electrode 374 will be higher, and the cost of the battery cell will be higher.

[0158] If the width of the outer electrode 374 is small, the outer electrode 374 will have poor current transmission capability, and the output power of the solar cell will be low.

[0159] Therefore, 0μm≤H1≤30μm can reduce the material cost of the outer electrode 374, thereby reducing the cost of the solar cell, and can also improve the current transmission capability of the outer electrode 374, thereby increasing the output power of the solar cell.

[0160] In the first direction Y, the number of outer electrodes 374 on one side of the inner electrode 375 is N2, where 1 ≤ N2 ≤ 10. The number of outer electrodes 374 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Here, the number of outer electrodes 374 refers to the number of electrodes arranged on one side of the battery cell. For example, on the side where the first edge 341 of the battery cell is located, that is, between the first edge welding structure 3511 and the first edge 341, the number of outer electrodes 374 is one or more.

[0161] Figure 16 The example shows that the number of outer electrodes 374 arranged on one side of the cell is one.

[0162] Figure 17 Figure 5 The enlarged structural view of part A in some other embodiments. Figure 17 The example illustrates that the number of outer electrodes 374 arranged on one side of the solar cell is multiple.

[0163] Based on the aforementioned battery cells, the pull-out force between the welding strip and the battery cells can be increased by adjusting the structure and arrangement of the welding structure 350. The structural design of the welding structure 350 is discussed in detail below.

[0164] Figure 18 for Figure 5 Enlarged views of part C in some embodiments. For example... Figure 18 As shown, the central welded structure 352 includes a main welded structure 3521 and a secondary welded structure 3522. In the third direction Z, the projected area of ​​the main welded structure 3521 is larger than the projected area of ​​the secondary welded structure 3522. Multiple main welded structures 3521 are arranged along the first direction Y, and at least two secondary welded structures 3522 are included between two adjacent main welded structures 3521.

[0165] In this embodiment, the area of ​​the main welding structure 3521 is larger than the area of ​​the secondary welding structure 3522, so that the welding area between the main welding structure 3521 and the welding strip is larger than the welding area between the secondary welding structure 3522 and the welding strip, thereby increasing the pull-out force between the welding strip and the battery cell, reducing the risk of the welding strip separating from the battery cell, and improving the anti-aging ability and performance of the battery cell.

[0166] The main welding structure 3521 has a large welding area with the welding strip, which can improve the current transmission capacity between the main welding structure 3521 and the welding strip, thereby improving the welding strip's ability to collect current, so as to improve the output power of the solar cell.

[0167] By setting up a main welding structure 3521 with a larger area and a secondary welding structure 3522 with a smaller area, the pull-out force between the welding strip and the battery cell and the current transmission capacity can be improved, while the amount of slurry required for the welding structure 350 can be reduced, thereby reducing the cost of the welding structure 350 and the battery cell.

[0168] In the second direction X, the width of the main welded structure 3521 is W1, and the width of the secondary welded structure 3522 is W2, where W2 < W1.

[0169] In this embodiment, under the premise that the area of ​​the main welding structure 3521 is greater than the area of ​​the sub-welding structure 3522, W2 < W1, which can reduce the distance between the sub-bus electrode 370 connected to the main welding structure 3521 and the sub-bus electrode 370 connected to the sub-welding structure 3522 in the first direction Y, which is beneficial to increasing the number of sub-bus electrodes 370 in the first direction Y, and thus improving the output power of the battery cell.

[0170] For example, the width of the main welded structure 3521 in the second direction X can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, etc., where 1mm ≤ W1 ≤ 3.5mm.

[0171] If the width of the main welding structure 3521 in the second direction X is small, and the distance between the secondary bus electrode 370 connected to the main welding structure 3521 and the secondary bus electrode 370 connected to the secondary welding structure 3522 in the first direction Y is a preset value, that is, when the size of the main welding structure 3521 in the first direction Y is a preset value, then the welding area between the main welding structure 3521 and the welding strip is small, and the pull-out force between the welding strip and the battery cell is small.

[0172] If the width of the main welding structure 3521 in the second direction X is small, and the area of ​​the main welding structure 3521 is a preset value, then the size of the main welding structure 3521 in the first direction Y is large. When the distance between the main welding structure 3521 and the auxiliary welding structure 3522 in the first direction Y is a preset value, then the distance between the auxiliary bus electrode 370 connected to the main welding structure 3521 and the auxiliary bus electrode 370 connected to the auxiliary welding structure 3522 in the first direction Y is large, and the number of auxiliary bus electrodes 370 in the first direction Y is small, which affects the output power of the battery cell.

[0173] If the width of the main welding structure 3521 in the second direction X is large, and the width of the welding strip in the second direction X is a preset value, and the area of ​​the main welding structure 3521 is a preset value, the size of the main welding structure 3521 in the first direction Y will be small. Then the welding area of ​​the main welding structure 3521 and the auxiliary welding structure 3522 with the welding strip will be small, and the pull-out force between the welding strip and the battery cell will be small.

[0174] If the width of the main welding structure 3521 in the second direction X is large, and the contact area between the main welding structure 3521 and the welding strip is a preset value, then the area of ​​the main welding structure 3521 is large, which makes the material cost of the main welding structure 3521 higher.

[0175] Therefore, 1mm≤W1≤3.5mm can increase the welding area between the main welding structure 3521 and the welding strip, thereby increasing the pull-out force of the welding strip on the cell. It can also reduce the material cost of the main welding structure 3521 and increase the number of auxiliary bus electrodes 370 to improve the output power of the cell.

[0176] For example, 1mm≤W1≤1.5mm, the width of the main welded structure 3521 in the second direction X can be 1mm, 1.01mm, 1.03mm, 1.05mm, 1.07mm, 1.09mm, 1.1mm, 1.11mm, 1.13mm, 1.15mm, 1.17mm, 1.19mm, 1.2mm, 1.21mm, 1.23mm, 1.25mm, 1.27mm, 1.29mm, 1.3mm, 1.31mm, 1.33mm, 1.35mm, 1.37mm, 1.39mm, 1.4mm, 1.41mm, 1.43mm, 1.45mm, 1.47mm, 1.49mm, 1.5mm, etc.

[0177] For example, 1.5mm≤W1≤2mm, the width of the main welded structure 3521 in the second direction X can be 1.5mm, 1.51mm, 1.53mm, 1.55mm, 1.57mm, 1.59mm, 1.6mm, 1.61mm, 1.63mm, 1.65mm, 1.67mm, 1.69mm, 1.7mm, 1.71mm, 1.73mm, 1.75mm, 1.77mm, 1.79mm, 1.8mm, 1.81mm, 1.83mm, 1.85mm, 1.87mm, 1.89mm, 1.9mm, 1.91mm, 1.93mm, 1.95mm, 1.97mm, 1.99mm, 2mm, etc.

[0178] For example, 2mm≤W1≤2.5mm, the width of the main welded structure 3521 in the second direction X can be 2mm, 2.01mm, 2.03mm, 2.05mm, 2.07mm, 2.09mm, 2.1mm, 2.11mm, 2.13mm, 2.15mm, 2.17mm, 2.19mm, 2.2mm, 2.21mm, 2.23mm, 2.25mm, 2.27mm, 2.29mm, 2.3mm, 2.31mm, 2.33mm, 2.35mm, 2.37mm, 2.39mm, 2.4mm, 2.41mm, 2.43mm, 2.45mm, 2.47mm, 2.49mm, 2.5mm, etc.

[0179] For example, 2.5mm≤W1≤3mm, the width of the main welded structure 3521 in the second direction X can be 2.5mm, 2.51mm, 2.53mm, 2.55mm, 2.57mm, 2.59mm, 2.6mm, 2.61mm, 2.63mm, 2.65mm, 2.67mm, 2.69mm, 2.7mm, 2.71mm, 2.73mm, 2.75mm, 2.77mm, 2.79mm, 2.8mm, 2.81mm, 2.83mm, 2.85mm, 2.87mm, 2.89mm, 2.9mm, 2.91mm, 2.93mm, 2.95mm, 2.97mm, 2.99mm, 3mm, etc.

[0180] For example, 3mm≤W1≤3.5mm, the width of the main welded structure 3521 in the second direction X can be 3mm, 3.01mm, 3.03mm, 3.05mm, 3.07mm, 3.09mm, 3.1mm, 3.11mm, 3.13mm, 3.15mm, 3.17mm, 3.19mm, 3.2mm, 3.21mm, 3.23mm, 3.25mm, 3.27mm, 3.29mm, 3.3mm, 3.31mm, 3.33mm, 3.35mm, 3.37mm, 3.39mm, 3.4mm, 3.41mm, 3.43mm, 3.45mm, 3.47mm, 3.49mm, 3.5mm, etc.

[0181] 0.3mm≤W2≤1.2mm, for example, the width of the sub-welded structure 3522 in the second direction X can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, etc.

[0182] If the width of the sub-welding structure 3522 in the second direction X is small, and the distance between the sub-bus electrode 370 connected to the main welding structure 3521 and the sub-bus electrode 370 connected to the sub-welding structure 3522 in the first direction Y is a preset value, that is, when the size of the sub-welding structure 3522 in the first direction Y is a preset value, then the welding area between the sub-welding structure 3522 and the welding strip is small, and the pull-out force between the welding strip and the battery cell is small.

[0183] If the width of the sub-welding structure 3522 in the second direction X is small, and the area of ​​the sub-welding structure 3522 is a preset value, then the size of the sub-welding structure 3522 in the first direction Y is large. When the distance between the sub-welding structure 3522 and the main welding structure 3521 in the first direction Y is a preset value, then the distance between the sub-bus electrode 370 connected to the main welding structure 3521 and the sub-bus electrode 370 connected to the sub-welding structure 3522 in the first direction Y is large, and the number of sub-bus electrodes 370 in the first direction Y is small, which affects the output power of the battery cell.

[0184] If the width of the sub-welding structure 3522 in the second direction X is large, and the width of the welding strip in the second direction X is a preset value, and the area of ​​the sub-welding structure 3522 is a preset value, the size of the sub-welding structure 3522 in the first direction Y will be small. Then the welding area of ​​the main welding structure 3521 and the sub-welding structure 3522 with the welding strip will be small, and the pull-out force between the welding strip and the battery cell will be small.

[0185] If the width of the sub-welding structure 3522 in the second direction X is large, and the contact area between the sub-welding structure 3522 and the welding strip is a preset value, then the area of ​​the sub-welding structure 3522 is large, which makes the material cost of the sub-welding structure 3522 high.

[0186] Therefore, 0.3mm≤W2≤1.2mm can increase the welding area between the sub-welding structure 3522 and the welding strip, thereby increasing the pull-out force of the welding strip on the cell. It can also reduce the material cost of the sub-welding structure 3522 and increase the number of sub-bus electrodes 370 to improve the output power of the cell.

[0187] For example, 0.3mm≤W2≤0.6mm, the width of the sub-welded structure 3522 in the second direction X can be 0.3mm, 0.31mm, 0.33mm, 0.35mm, 0.37mm, 0.39mm, 0.4mm, 0.41mm, 0.43mm, 0.45mm, 0.47mm, 0.49mm, 0.5mm, 0.51mm, 0.53mm, 0.55mm, 0.57mm, 0.59mm, 0.6mm, etc.

[0188] For example, 0.6mm≤W2≤0.9mm, the width of the sub-welded structure 3522 in the second direction X can be 0.6mm, 0.61mm, 0.63mm, 0.65mm, 0.67mm, 0.69mm, 0.7mm, 0.71mm, 0.73mm, 0.75mm, 0.77mm, 0.79mm, 0.8mm, 0.81mm, 0.83mm, 0.85mm, 0.87mm, 0.89mm, 0.9mm, etc.

[0189] For example, 0.9mm≤W2≤1.2mm, the width of the sub-welded structure 3522 in the second direction X can be 0.9mm, 0.91mm, 0.93mm, 0.95mm, 0.97mm, 0.99mm, 1mm, 1.01mm, 1.03mm, 1.05mm, 1.07mm, 1.09mm, 1.1mm, 1.11mm, 1.13mm, 1.15mm, 1.17mm, 1.19mm, 1.2mm, etc.

[0190] In some embodiments, on the third-party direction Z, the projected area of ​​the edge weld structure 351 is equal to the projected area of ​​the main weld structure 3521.

[0191] In other implementations, on the third-party Z-axis, the projected area of ​​the edge welding structure 351 is larger than the projected area of ​​the main welding structure 3521, so as to improve the welding strength between the edge of the cell and the solder strip, thereby increasing the pull-out force of the solder strip at the edge of the cell, reducing the risk of the solder strip detaching from the cell, and improving the anti-aging ability and performance of the cell.

[0192] like Figure 18 As shown, in the first direction Y, at least three sub-welding structures 3522 are included between the edge welding structure 351 and the adjacent main welding structure 3521 to increase the pull-out force of the welding strip at the edge of the cell, reduce the risk of the welding strip detaching from the cell, and improve the anti-aging ability and performance of the cell.

[0193] The edge welding structure 351 and the adjacent main welding structure 3521 include at least three sub-welding structures 3522. While meeting the pull-out force of the welding strip at the edge of the cell, the material cost of the welding structure 350 can be reduced, thereby reducing the cost of the cell.

[0194] The outline shape of the welded structure 350 includes, but is not limited to, circles, triangles, quadrilaterals, rectangles, T-shapes, I-shapes, Z-shapes, etc. The embodiments of this application do not impose special limitations on the shape of the welded structure 350.

[0195] Figure 19 for Figure 5The enlarged view of part C in some embodiments. In some embodiments, the outline shape of the main welded structure 3521 is circular or rectangular, and the outline shape of the secondary welded structure 3522 is T-shaped, I-shaped or Z-shaped.

[0196] In this embodiment, the outline shape of the main welding structure 3521 is circular or rectangular, so as to increase the area of ​​the main welding structure 3521 and improve the current transmission efficiency and pull-out force between the main welding structure 3521 and the welding strip.

[0197] The outline shape of the sub-welding structure 3522 is T-shaped, I-shaped or Z-shaped. Under the premise that the area of ​​the sub-welding structure 3522 is small, it can increase and improve the welding stress between the sub-welding structure 3522 and the welding strip, reduce the phenomenon of local stress concentration, reduce the risk of damage caused by fatigue or repeated load, and improve the anti-aging ability of the cell.

[0198] Figure 20 for Figure 5 Enlarged view of part C in some embodiments. In some embodiments, such as Figure 20 As shown, the number of welding structures 350 and secondary bus electrodes 370 in the first direction Y is the same, that is, the number of secondary bus electrodes 370 between two adjacent welding structures 350 is 0, so that each secondary bus electrode 370 is electrically connected to the welding strip through the welding structure 350. This increases the number of welding structures 350, improves the pull-out force between the welding structure 350 and the solar cell, and also improves the current collection efficiency of the welding strip on the solar cell, thereby improving the output power of the solar cell.

[0199] Figure 21 for Figure 5 Enlarged view of part D in some embodiments. In other embodiments, such as Figure 21 As shown, in the first direction Y, at least one secondary bus electrode 370 is included between two adjacent welded structures 350 to reduce the number of welded structures 350, thereby reducing the material cost of the welded structures 350 and thus reducing the cost of the solar cell.

[0200] Among them, such as Figure 21 As shown, the welding structure 350 and the auxiliary bus electrode 370 can be periodically arranged in the first direction Y to improve the stress distribution between the solder strip and the cell and reduce the risk of damage to the cell or solder strip caused by stress concentration.

[0201] Continue to refer to Figure 20When the number of secondary bus electrodes 370 between two adjacent welding structures 350 is 0, the secondary bus electrode 370 includes a main welding electrode 376 and a secondary welding electrode 377. The end of the main welding electrode 376 contacts the main welding structure 3521, and the end of the secondary welding electrode 377 contacts the secondary welding structure 3522. In the first direction Y, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 is H2, and the distance between two adjacent secondary welding electrodes 377 is H3, where 0.3 ≤ H2 / H3 ≤ 7. For example, the ratio of H2 to H3 can be 0.3, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, etc.

[0202] For example, 0.3≤H2 / H3≤1, and the ratio of H2 to H3 can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0203] For example, 1≤H2 / H3≤3, and the ratio of H2 to H3 can be 1, 1.1, 1.3, 1.5, 1.7, 1.9, 2, 2.1, 2.2, 2.3, 2.5, 2.7, 2.9, 3, etc.

[0204] For example, 3≤H2 / H3≤5, and the ratio of H2 to H3 can be 3, 3.1, 3.3, 3.5, 3.7, 3.9, 4, 4.1, 4.2, 4.3, 4.5, 4.7, 4.9, 5, etc.

[0205] For example, 5 ≤ H2 / H3 ≤ 7, and the ratio of H2 to H3 can be 5, 5.1, 5.3, 5.5, 5.7, 5.9, 6, 6.1, 6.2, 6.3, 6.5, 6.7, 6.9, 7, etc.

[0206] And H3 < H2.

[0207] In this embodiment, the distance between the main welding electrode 376 and its adjacent sub-welding electrode 377 is relatively large, while the distance between two adjacent sub-welding electrodes 377 is relatively small. This results in a larger spacing between the main welding structure 3521 and its adjacent sub-welding structure 3522, and a smaller spacing between adjacent sub-welding structures 3522. This reduces the risk of contact between the main welding structure 3521 and its adjacent sub-welding structure 3522, thereby reducing the risk of reduced efficiency due to a large surface area of ​​the solar cell being obscured, and thus improving the output power of the solar cell. Simultaneously, the smaller spacing between adjacent sub-welding structures 3522 allows for an increase in the number of sub-welding structures 3522, which in turn improves the pull-out force between the solder strip and the solar cell, thereby enhancing the anti-aging performance of the solar cell.

[0208] 0.5mm≤H2≤2mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc.

[0209] If the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 is small, there is a greater risk that the main welding structure 3521 and its adjacent secondary welding structure 3522 will come into contact, which will increase the risk of the solar cell's shading area and affect the solar cell's output power.

[0210] If the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 is small, the number of secondary bus electrodes 370 will be large, resulting in a higher cost for the solar cell.

[0211] If the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 is large, the number of welding structures 350 will be small, affecting the pull-out force between the welding strip and the cell, thus improving the anti-aging performance of the cell.

[0212] If the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 is large, the number of secondary bus electrodes 370 will be small, resulting in lower current collection efficiency of the solar cell and affecting the output power of the solar cell.

[0213] Therefore, a thickness of 0.5mm ≤ H2 ≤ 2mm can reduce the shading area of ​​the solar cell by the welding structure 350, thereby increasing the output power of the solar cell. Simultaneously, it can increase the number of welding structures 350 to improve the pull-out force between the solder strip and the solar cell, thus enhancing the solar cell's anti-aging performance. Furthermore, it can increase the output power of the solar cell while reducing its material cost.

[0214] For example, 0.5mm≤H2≤0.7mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm, 0.6mm, 0.61mm, 0.62mm, 0.63mm, 0.64mm, 0.65mm, 0.66mm, 0.67mm, 0.68mm, 0.69mm, 0.7mm, etc.

[0215] For example, 0.7mm≤H2≤0.9mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm, 0.8mm, 0.81mm, 0.82mm, 0.83mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.89mm, 0.9mm, etc.

[0216] For example, 0.9mm≤H2≤1.1mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 0.9mm, 0.91mm, 0.92mm, 0.93mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 0.99mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 1.1mm, etc.

[0217] For example, 1.1mm≤H2≤1.3mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 1.1mm, 1.11mm, 1.12mm, 1.13mm, 1.14mm, 1.15mm, 1.16mm, 1.17mm, 1.18mm, 1.19mm, 1.2mm, 1.21mm, 1.22mm, 1.23mm, 1.24mm, 1.25mm, 1.26mm, 1.27mm, 1.28mm, 1.29mm, 1.3mm, etc.

[0218] For example, 1.3mm≤H2≤1.5mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 1.3mm, 1.31mm, 1.32mm, 1.33mm, 1.34mm, 1.35mm, 1.36mm, 1.37mm, 1.38mm, 1.39mm, 1.4mm, 1.41mm, 1.42mm, 1.43mm, 1.44mm, 1.45mm, 1.46mm, 1.47mm, 1.48mm, 1.49mm, 1.5mm, etc.

[0219] For example, 1.5mm≤H2≤1.7mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 1.5mm, 1.51mm, 1.52mm, 1.53mm, 1.54mm, 1.55mm, 1.56mm, 1.57mm, 1.58mm, 1.59mm, 1.6mm, 1.61mm, 1.62mm, 1.63mm, 1.64mm, 1.65mm, 1.66mm, 1.67mm, 1.68mm, 1.69mm, 1.7mm, etc.

[0220] For example, 1.7mm≤H2≤1.9mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 1.7mm, 1.71mm, 1.72mm, 1.73mm, 1.74mm, 1.75mm, 1.76mm, 1.77mm, 1.78mm, 1.79mm, 1.8mm, 1.81mm, 1.82mm, 1.83mm, 1.84mm, 1.85mm, 1.86mm, 1.87mm, 1.88mm, 1.89mm, 1.9mm, etc.

[0221] For example, 1.9mm≤H2≤2mm, the distance between the main welding electrode 376 and its adjacent secondary welding electrode 377 can be 1.9mm, 1.905mm, 1.91mm, 1.915mm, 1.92mm, 1.925mm, 1.93mm, 1.935mm, 1.94mm, 1.945mm, 1.95mm, 1.955mm, 1.96mm, 1.965mm, 1.97mm, 1.975mm, 1.98mm, 1.985mm, 1.99mm, 1.995mm, 2mm, etc.

[0222] 0.3mm≤H3≤1.5mm, the distance between two adjacent secondary welding electrodes 377 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc.

[0223] If the distance between two adjacent sub-welding electrodes 377 is small, the risk of contact between the two adjacent sub-welding structures 3522 is high, which increases the risk of increased shading area of ​​the solar cell and affects the output power of the solar cell.

[0224] If the distance between two adjacent secondary welding electrodes 377 is small, the number of secondary bus electrodes 370 will be large, resulting in a higher cost for the solar cell.

[0225] If the distance between two adjacent secondary welding electrodes 377 is large, the number of welding structures 350 will be small, affecting the pull-out force between the welding strip and the cell, thus improving the anti-aging performance of the cell.

[0226] If the distance between two adjacent secondary welding electrodes 377 is large, the number of secondary bus electrodes 370 will be small, resulting in lower current collection efficiency of the solar cell and affecting the output power of the solar cell.

[0227] Therefore, a thickness of 0.3mm ≤ H3 ≤ 1.5mm can reduce the shading area of ​​the solar cell by the welding structure 350, thereby increasing the output power of the solar cell. Simultaneously, it can increase the number of welding structures 350 to improve the pull-out force between the weld strip and the solar cell, thus enhancing the solar cell's anti-aging performance. Furthermore, it can increase the output power of the solar cell while reducing its material cost.

[0228] For example, 0.3mm≤H3≤0.5mm, the distance between two adjacent secondary welding electrodes 377 can be 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm, 0.5mm, etc.

[0229] For example, 0.5mm≤H3≤0.7mm, the distance between two adjacent secondary welding electrodes 377 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm, 0.6mm, 0.61mm, 0.62mm, 0.63mm, 0.64mm, 0.65mm, 0.66mm, 0.67mm, 0.68mm, 0.69mm, 0.7mm, etc.

[0230] For example, 0.7mm≤H3≤0.9mm, the distance between two adjacent secondary welding electrodes 377 can be 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm, 0.8mm, 0.81mm, 0.82mm, 0.83mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.89mm, 0.9mm, etc.

[0231] For example, 0.9mm≤H3≤1.1mm, the distance between two adjacent secondary welding electrodes 377 can be 0.9mm, 0.91mm, 0.92mm, 0.93mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 0.99mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 1.1mm, etc.

[0232] For example, 1.1mm≤H3≤1.3mm, the distance between two adjacent secondary welding electrodes 377 can be 1.1mm, 1.11mm, 1.12mm, 1.13mm, 1.14mm, 1.15mm, 1.16mm, 1.17mm, 1.18mm, 1.19mm, 1.2mm, 1.21mm, 1.22mm, 1.23mm, 1.24mm, 1.25mm, 1.26mm, 1.27mm, 1.28mm, 1.29mm, 1.3mm, etc.

[0233] For example, 1.3mm≤H3≤1.5mm, the distance between two adjacent secondary welding electrodes 377 can be 1.3mm, 1.31mm, 1.32mm, 1.33mm, 1.34mm, 1.35mm, 1.36mm, 1.37mm, 1.38mm, 1.39mm, 1.4mm, 1.41mm, 1.42mm, 1.43mm, 1.44mm, 1.45mm, 1.46mm, 1.47mm, 1.48mm, 1.49mm, 1.5mm, etc.

[0234] The solar cell may or may not include the main bus electrode 380.

[0235] Figure 22 This is a schematic diagram of a partial structure of the battery cell in some embodiments. For example... Figure 22 As shown, the battery cell also includes a main bus electrode 380 extending along the first direction Y, a secondary bus electrode 370 connected to the main bus electrode 380, and at least a portion of the welded structure 350 located on the main bus electrode 380.

[0236] At this time, the secondary bus electrode 370 and the welding structure 350 can be indirectly electrically connected through the main bus electrode 380, or the secondary bus electrode 370 and the welding structure 350 can be directly electrically connected.

[0237] Figure 23 for Figure 22 Enlarged view of part E in some embodiments. Figure 23An example is provided whereby the secondary bus electrode 370 and the welding structure 350 can be indirectly electrically connected through the main bus electrode 380. That is, the welding structure 350 is disposed on the main bus electrode 380, the secondary bus electrode 370 is connected to the main bus electrode 380, and the secondary bus electrode 370 and the welding structure 350 are arranged at intervals in the first direction Y.

[0238] Figure 24 for Figure 22 Enlarged view of part E in other embodiments. Figure 24 An example of the electrical connection between the secondary bus electrode 370 and the weld structure 350 is shown.

[0239] like Figure 22 As shown, multiple main bus electrodes 380 are arranged at intervals along the second direction X. The number of main bus electrodes 380 in the second direction X is N3, where 5≤N3≤24. The number of main bus electrodes 380 in the second direction X can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

[0240] If the number of main bus electrodes 380 is small, the current collection efficiency is low, and the length of the secondary bus electrode 370 in the second direction Y is extended, thereby increasing the resistance in the current transmission process and affecting the output power of the cell.

[0241] If there are many main bus electrodes 380, the main bus electrodes 380 will block a large area of ​​the solar cell, which will affect the output power of the solar cell and increase the cost of the solar cell paste.

[0242] Therefore, 5≤N3≤24 improves the current collection efficiency of the solar cell and reduces the resistance during current transmission. At the same time, it reduces the shading area of ​​the main bus electrode 380 on the solar cell, which helps to improve the output power of the solar cell and reduce the material cost of the solar cell.

[0243] like Figure 22 As shown, the welded structures 350 arranged along the first direction Y form a welded column 353, and multiple welded columns 353 are arranged along the second direction X.

[0244] Figure 25 This is a schematic diagram of a partial structure of the battery cell in some other embodiments. In some embodiments, such as Figure 25 As shown, in the second direction X, the number of main bus electrodes 380 is the same as the number of welding columns 353. The main bus electrodes 380 and welding columns 353 correspond one-to-one to improve the current collection efficiency of the solar cell.

[0245] In other embodiments, such as Figure 22As shown, in the second direction X, the number of main bus electrodes 380 is less than the number of welding columns 353, that is, there is at least one welding column 353 between two adjacent main bus electrodes 380 that is not connected to the main bus electrode 380. While reducing the number of main bus electrodes 380, the number of welding strips is increased, thereby improving the output power of the cell.

[0246] In some embodiments, the number of main bus electrodes 380 in the first direction Y is one, that is, in the first direction Y, all welding structures 350 in a welding column 353 are disposed on the same main bus electrode 380.

[0247] In other embodiments, multiple main bus electrodes 380 are arranged at intervals along a first direction Y. That is, in the first direction Y, some welding structures 350 in a welding column 353 are disposed on the main bus electrodes 380, and some welding structures 350 are not disposed on the main bus electrodes 380, so as to reduce the material cost of the main bus electrodes 380 and reduce the shading area of ​​the main bus electrodes 380 on the solar cell, thereby improving the output power of the solar cell.

[0248] When the solar cell does not include the main bus electrode 380 Figure 26 This is a partial structural diagram of a battery cell in some embodiments. Figure 27 for Figure 26 The F portion in the diagram is shown in enlarged structural views in some embodiments. Also refer to... Figure 26 and Figure 27 The welding structure 350 is directly connected to the auxiliary bus electrode 370 to reduce the cost of the cell paste and reduce the shading on the surface of the cell, which is beneficial to improving the output power of the cell.

[0249] The second aspect of this application provides a photovoltaic module. Figure 28 The following are schematic diagrams of the structure of the photovoltaic module provided in this application in some embodiments, such as... Figure 22 As shown, the photovoltaic module includes an encapsulation plate 100, an encapsulation layer 200, and a cell layer 300.

[0250] The encapsulation board 100 includes a first encapsulation board 110 and a second encapsulation board 120 arranged along the third direction Z. The encapsulation layer 200 and the battery layer 300 are located between the first encapsulation board 110 and the second encapsulation board 120. A portion of the encapsulation layer 200 is located between the battery layer 300 and the first encapsulation board 110, and another portion of the encapsulation layer 200 is located between the battery layer 300 and the second encapsulation board 120, so as to achieve the encapsulation and fixation of the encapsulation board 100 and the battery layer 300.

[0251] At least one of the first encapsulation plate 110 and the second encapsulation plate 120 is made of a light-transmitting material, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0252] The first encapsulation plate 110 can be made of one of the following rigid materials: tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the first encapsulation plate 110 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.

[0253] The material of the second encapsulation plate 120 can be one of rigid materials such as tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the material of the second encapsulation plate 120 can be one of flexible materials such as PVF (polyvinyl fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), or PVDF (polyvinylidene fluoride).

[0254] The materials of the first encapsulation plate 110 and the second encapsulation plate 120 can be the same or different.

[0255] like Figure 28 As shown, the encapsulation layer 200 includes a first adhesive film 210 and a second adhesive film 220. In the third direction Z, a portion of the structure of the first adhesive film 210 is located between the battery layer 300 and the first encapsulation plate 110, and a portion of the structure of the second adhesive film 220 is located between the battery layer 300 and the second encapsulation plate 120.

[0256] The first encapsulant film 210 is made of one of the following polyolefins: EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), or PVB (Polyvinyl Butyral). These materials have high light transmittance, which is beneficial for improving the photoelectric conversion efficiency of photovoltaic modules. The first encapsulant film 210 can also be an EPE film (EVA-POE-EVA co-extrusion structure) or an EP film (EVA-POE co-extrusion structure).

[0257] The material of the second film 220 is one of polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral). The second film 220 can also be an EPE film (EVA-POE-EVA co-extrusion structure) or an EP film (EVA-POE co-extrusion structure).

[0258] The materials of the first adhesive film 210 and the second adhesive film 220 can be the same or different.

[0259] Figure 29 This is a schematic diagram of the connection structure of the battery layer in some embodiments, such as... Figure 29 As shown, the battery layer 300 includes multiple battery strings connected in series or in parallel. Each battery string is composed of multiple battery cells 310 connected in series. The battery cells 310 include, but are not limited to, monocrystalline silicon battery cells and polycrystalline silicon battery cells. Adjacent battery cells 310 are connected by solder ribbons 320. The solder ribbons 320 are welded and fixed to the welding structure on the battery cells 310. The battery cells 310 are the aforementioned battery cells.

[0260] Figure 30 This is a schematic diagram of the battery layer structure in some embodiments, such as... Figure 30 As shown, the battery layer 300 also includes a busbar 330. Along the first direction Y, the busbar 330 is located on both sides of the battery string and is used to realize the series or parallel connection between multiple battery strings.

[0261] 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 type of battery cell, characterized in that, The battery cell includes a substrate (340) and a welding structure (350), a busbar (360) and a busbar electrode disposed on the substrate (340); The plurality of said welded structures (350) are arranged along a first direction (Y), the welded structure (350) includes an outermost edge welded structure (351) located in the first direction (Y), the welded structure (350) also includes a middle welded structure (352), the middle welded structure (352) being located on one side of the edge welded structure (351) in the first direction (Y); The confluence harpoon (360) is located on the side of the edge welded structure (351) away from the middle welded structure (352), and the confluence harpoon (360) includes a harpoon gap (363); The bus electrode includes at least a secondary bus electrode (370) extending along a second direction (X), the secondary bus electrode (370) including a first electrode (371) and a second electrode (372), in the first direction (Y), the first electrode (371) and the second electrode (372) are both located on the side of the edge welding structure (351) away from the middle welding structure (352), the first electrode (371) is located between the second electrode (372) and the edge welding structure (351); Both the first electrode (371) and the second electrode (372) are connected to the harpoon (360). The first electrode (371) passes through the harpoon gap (363) along the second direction (X), and the second electrode (372) is disconnected at the harpoon gap (363). The battery cell includes an edge region (343) located on the side of the outermost first electrode (371) away from the edge welding structure (351) in the first direction (Y). In the first direction (Y), the spacing of at least a portion of the sub-bus electrodes (370) in the edge region (343) is smaller than the spacing of the sub-bus electrodes (370) in the remaining regions.

2. The battery cell according to claim 1, characterized in that, Within the edge region (343), the number of second electrodes (372) arranged in the first direction (Y) is one; In the first direction (Y), the distance between adjacent first electrodes (371) is L1, and the distance between the second electrode (372) and its adjacent first electrode (371) is L2, where L2 < L1.

3. The battery cell according to claim 1, characterized in that, Within the edge region (343), the number of second electrodes (372) arranged in the first direction (Y) is at least two; In the first direction (Y), the distance between adjacent first electrodes (371) is L1, the distance between the outermost first electrode (371) and its adjacent second electrode (372) is L2, and the distance between adjacent second electrodes (372) is L3. L2 < L1, and / or, L3 < L1.

4. The battery cell according to claim 1, characterized in that, Within the edge region (343), the number of the second electrodes (372) arranged in the first direction (Y) is N1, where 1≤N1≤10.

5. The battery cell according to claim 1, characterized in that, The substrate (340) includes a first edge (341) and a second edge (342) arranged along the first direction (Y), and the edge welding structure (351) includes a first edge welding structure (3511) and a second edge welding structure (3512) arranged along the first direction (Y). In the first direction (Y), the first edge welding structure (3511) is located between the first edge (341) and the second edge welding structure (3512). In the first direction (Y), the confluence harpoon (360) is provided between the first edge welding structure (3511) and the first edge (341), and between the second edge welding structure (3512) and the second edge (342); In the first direction (Y), the first electrode (371) and the second electrode (372) are located between the first edge welding structure (3511) and the first edge (341); The secondary bus electrode (370) further includes a third electrode (373), which is located between the second edge welding structure (3512) and the second edge (342) in the first direction (Y). The third electrode (373) is connected to the bus harpoon (360) and extends through the harpoon gap (363) along the second direction (X). The plurality of the third electrodes (373) are arranged along the first direction (Y), in which the cell includes an outermost edge electrode, and the third electrodes (373) are configured as the edge electrode.

6. The battery cell according to claim 5, characterized in that, In the thickness direction of the battery cell, the first electrode (371), the second electrode (372), and the third electrode (373) are located on the same side of the substrate (340); Alternatively, in the thickness direction of the battery cell, the first electrode (371) and the second electrode (372) are located on one side of the substrate (340), and the third electrode (373) is located on the other side of the substrate (340).

7. The battery cell according to any one of claims 1 to 6, characterized in that, In the first direction (Y), the battery cell includes an outer electrode (374) located on the outside and an inner electrode (375) located on the inside, with the outer electrode (374) located on both sides of the inner electrode (375) in the first direction (Y). In the first direction (Y), the width of the outer electrode (374) is greater than the width of the inner electrode (375).

8. The battery cell according to claim 7, characterized in that, In the first direction (Y), the width of the outer electrode (374) is H1, 10μm≤H1≤30μm.

9. The battery cell according to claim 7, characterized in that, In the first direction (Y), the number of the outer electrodes (374) on one side of the inner electrode (375) is N2, 1≤N2≤10.

10. The battery cell according to any one of claims 1 to 6, characterized in that, The central welded structure (352) includes a main welded structure (3521) and a secondary welded structure (3522). A plurality of the main welded structures (3521) are arranged along the first direction (Y), and at least two secondary welded structures (3522) are included between two adjacent main welded structures (3521). In the thickness direction of the battery cell, the projected area of ​​the main welding structure (3521) is larger than the projected area of ​​the secondary welding structure (3522).

11. The battery cell according to claim 10, characterized in that, In the first direction (Y), at least three of the sub-welded structures (3522) are included between the edge welded structure (351) and the adjacent main welded structure (3521).

12. The battery cell according to claim 10, characterized in that, In the second direction (X), the width of the main welded structure (3521) is W1, and the width of the secondary welded structure (3522) is W2, where W2 < W1; 1mm≤W1≤3.5mm, 0.3mm≤W2≤1.2mm.

13. The battery cell according to claim 10, characterized in that, The outline shape of the main welded structure (3521) is circular or rectangular; The outline shape of the sub-welded structure (3522) is T-shaped, I-shaped or Z-shaped.

14. The battery cell according to any one of claims 1 to 6, characterized in that, In the first direction (Y), the number of secondary bus electrodes (370) between two adjacent welded structures (350) is 0, or at least one secondary bus electrode (370) is included between two adjacent welded structures (350); The welding structure (350) and the secondary bus electrode (370) are periodically arranged in the first direction (Y).

15. The battery cell according to claim 14, characterized in that, In the first direction (Y), the number of secondary bus electrodes (370) between two adjacent welding structures (350) is 0; The central welding structure (352) includes a main welding structure (3521) and a secondary welding structure (3522). In the thickness direction of the battery cell, the projected area of ​​the main welding structure (3521) is larger than the projected area of ​​the secondary welding structure (3522). The secondary bus electrode (370) includes a main welding electrode (376) and a secondary welding electrode (377). The end of the main welding electrode (376) is in contact with the main welding structure (3521), and the end of the secondary welding electrode (377) is in contact with the secondary welding structure (3522). In the first direction (Y), the distance between the main welding electrode (376) and the adjacent secondary welding electrode (377) is H2, and the distance between two adjacent secondary welding electrodes (377) is H3, where 0.3≤H2 / H3≤7.

16. The battery cell according to claim 15, characterized in that, 0.5mm≤H2≤2mm, 0.3mm≤H3≤1.5mm, and H3<H2.

17. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell has no main bus electrode, and the welding structure (350) is directly connected to the auxiliary bus electrode (370).

18. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell also includes a main bus electrode (380) extending along the first direction (Y), the auxiliary bus electrode (370) being connected to the main bus electrode (380), and at least a portion of the welding structure (350) being located on the main bus electrode (380); The plurality of main bus electrodes (380) are arranged at intervals along the second direction (X), and the number of the main bus electrodes (380) in the second direction (X) is N3, where 5≤N3≤24.

19. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell also includes a main bus electrode (380) extending along the first direction (Y), the auxiliary bus electrode (370) being connected to the main bus electrode (380), and at least a portion of the welding structure (350) being located on the main bus electrode (380); The plurality of main bus electrodes (380) are arranged at intervals along the second direction (X); Welded structures (350) arranged along the first direction (Y) form a welded column (20), and multiple welded columns (20) are arranged along the second direction (X); In the second direction (X), the number of the main bus electrodes (380) is the same as the number of the welding columns (20); Alternatively, in the second direction (X), the number of main bus electrodes (380) is less than the number of weld columns (20), and at least one weld column (20) is included between two adjacent main bus electrodes (380).

20. A photovoltaic module, characterized in that, The photovoltaic module includes an encapsulation plate (100), an encapsulation layer (200), and a cell layer (300), wherein the cell layer (300) includes a plurality of cell cells according to any one of claims 1 to 19.

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