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 body, a solder pad, a fish-tail structure and a fine grid. The solder pad comprises an edge solder pad and a middle solder pad, and the middle solder pad is located on one side of the edge solder pad in a first direction. The fish-tail structure is located on the side of the edge solder pad away from the middle solder pad in the first direction, and the fish-tail structure comprises a fish-tail gap. A first fine grid and a second fine grid are arranged on the side of the edge solder pad away from the middle solder pad, and the first fine grid is located between the second fine grid and the edge solder pad. The first fine grid is disconnected at the fish-tail gap, and the second fine grid penetrates through the fish-tail gap in a second direction, so that the current collection path is optimized, the current transmission loss is reduced, and the output power of the cell piece is 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 grid and fine grids, which extend orthogonally. The main grid has pads for welding and fixing to the solder strip, thereby enabling current collection and transmission. A harpoon structure is located at the end of the main grid, and a portion of the fine grid is electrically connected to the harpoon structure to collect current from that portion of the fine grid.

[0003] Typically, the fine grids connected to the harpoon structure will penetrate the harpoon structure, causing the current collection path of the solar cell to deteriorate, thus affecting the efficiency of the solar cell.

[0004] Therefore, optimizing the current harvesting path 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 solar cell, including a body, pads, a harpoon structure, and a fine grid. A plurality of pads are arranged along a first direction, including an outermost edge pad located in the first direction, and a central pad located on one side of the edge pads in the first direction. The body also includes a light-facing surface and a back-light-facing surface distributed along the thickness direction of the solar cell. At least one of the light-facing surface and the back-light-facing surface is provided with a harpoon structure located on the side of the edge pads away from the central pads in the first direction, and the harpoon structure includes a harpoon gap. The fine grid includes a first fine grid and a second fine grid. In the first direction, both the first and second fine grids are located on the side of the edge pads away from the central pads, with the first fine grid located between the second fine grid and the edge pads. Both the first and second fine grids are connected to the harpoon structure, the first fine grid is disconnected at the harpoon gap, and the second fine grid extends through the harpoon gap along a second direction.

[0007] In this application, the current on the first and second fine grids can be transmitted to the edge pads through the harpoon structure, and then to the solder strip through the edge pads, so as to realize the collection and transmission of the current on the first and second fine grids, improve the current collection efficiency at the edge of the cell, and increase the output power of the cell.

[0008] The first fine grid is broken at the harpoon structure, which reduces the amount of paste required for the first fine grid, lowers the material cost of the first fine grid, and helps to reduce the cost of the solar cell.

[0009] The second fine grid extends through the harpoon structure, meaning the second fine grid is not broken at the harpoon structure. This optimizes the current collection path, helps reduce current transmission loss, and improves the output power of the solar cell.

[0010] In some possible designs, the number of first fine grids arranged in the first direction is N1, where 1≤N1≤10.

[0011] In some possible designs, in the first direction, the cell includes an outermost edge grid and a second grid is configured as an edge grid.

[0012] In some possible designs, the fine grid also includes a third fine grid, which is located on the side of the second fine grid opposite to the first fine grid in the first direction. The third fine grid is connected to the harpoon structure and is disconnected at the harpoon gap.

[0013] In some possible designs, the number of third fine grids arranged in the first direction is N2, where 1≤N2≤10.

[0014] In some possible designs, the body includes a first edge and a second edge arranged along a first direction, and edge pads include a first edge pad and a second edge pad arranged along the first direction. In the first direction, the first edge pad is located between the first edge and the second edge pad. In the first direction, a harpoon structure, a first fine gate, and a second fine gate are disposed between the first edge pad and the first edge, and a harpoon structure, a first fine gate, and a second fine gate are disposed between the second edge pad and the second edge.

[0015] In some possible designs, the body includes a first edge and a second edge arranged along a first direction, and edge pads including first edge pads and second edge pads arranged along the first direction, wherein the first edge pads are located between the first edge and the second edge pads in the first direction. A harpoon structure is provided between the first edge pads and the first edge, and between the second edge pads and the second edge, both in the first direction. A first fine gate and a second fine gate are located between the first edge pads and the first edge in the first direction. The fine gate also includes a fourth fine gate, which is located between the second edge pads and the second edge in the first direction, connected to the harpoon structure, and extending through the harpoon gap along a second direction.

[0016] In some possible designs, the grating also includes a fifth grating, which is located between the fourth grating and the second edge in the first direction. The fifth grating is connected to the harpoon structure and is disconnected at the harpoon gap.

[0017] In some possible designs, the number of fifth fine grids arranged in the first direction is N3, where 1≤N3≤10.

[0018] In some possible designs, the central pad includes a main pad and a secondary pad, with multiple main pads arranged along a first direction, and at least two secondary pads between two adjacent main pads. In the thickness direction of the cell, the projected area of ​​the main pad is larger than the projected area of ​​the secondary pad.

[0019] In some possible designs, the width of the main pad in the second direction is W1, and the width of the secondary pad in the second direction is W2, where W2 < W1. 1mm ≤ W1 ≤ 3.5mm, 0.3mm ≤ W2 ≤ 1.2mm.

[0020] In some possible designs, in the first direction, there are at least three sub-pads between the edge pad and the adjacent main pad.

[0021] In some possible designs, the outline shape of the primary pad is circular or rectangular. The outline shape of the secondary pad is T-shaped, I-shaped, or Z-shaped.

[0022] In some possible designs, the number of fine gates between two adjacent pads is 0 in the first direction, or at least one fine gate is included between two adjacent pads. The pads and fine gates are arranged periodically in the first direction.

[0023] In some possible designs, the number of fine gates between two adjacent pads is 0 in the first direction. The middle pads include a main pad and a sub-pad; in the thickness direction of the cell, the projected area of ​​the main pad is larger than that of the sub-pad. The fine gates include a main fine gate and a sub-fine gate; the end of the main fine gate contacts the main pad, and the end of the sub-fine gate contacts the sub-pad. In the first direction, the distance between the main fine gate and its adjacent sub-fine gate is L1, and the distance between two adjacent sub-fine gates is L2, where 0.3 ≤ L1 / L2 ≤ 7.

[0024] In some possible designs, 0.5mm≤L1≤2mm, 0.3mm≤L2≤1.5mm, and L2<L1.

[0025] In some possible designs, the solar cells are gridless cells, with the pads directly connected to the grid.

[0026] In some possible designs, the solar cell also includes a main grid extending along a first direction, with fine grids connected to the main grid, and at least some pads located on the main grid. Multiple main grids are arranged at intervals along a second direction, with the number of main grids in the second direction being N⁴, where 5 ≤ N⁴ ≤ 2⁴.

[0027] In some possible designs, pads arranged along a first direction form a pad column, and multiple pad columns are arranged along a second direction. In the second direction, the number of main gates is the same as the number of pad columns. Alternatively, in the second direction, the number of main gates is less than the number of pad columns, and at least one pad column is included between two adjacent main gates.

[0028] In some possible designs, the solar cell also includes a main grid extending along a first direction, with fine grids connected to the main grid, and at least some pads located on the main grid. The number of main grids in the first direction is one, or multiple main grids are arranged at intervals along the first direction.

[0029] A second aspect of this application provides a photovoltaic module, including a cover plate, an encapsulation layer, and a cell layer, wherein the cell layer includes a plurality of cells as described in any one of the claims.

[0030] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The diagram shows the structure of the battery cell provided in this application in some embodiments.

[0033] Figure 2 The diagram shows the structure of the battery cell provided in this application in some other embodiments;

[0034] Figure 3 A schematic diagram of the structure of the battery cell provided in this application in some other embodiments;

[0035] Figure 4 A partial structural schematic diagram of the battery cell provided in this application in some embodiments;

[0036] Figure 5 A partial structural diagram of the battery cell provided in this application in some other embodiments;

[0037] Figure 6 for Figure 5 Enlarged view of part A in some embodiments;

[0038] Figure 7 for Figure 5 Enlarged view of part A in some other embodiments;

[0039] Figure 8 for Figure 5 Enlarged view of part A in some other embodiments;

[0040] Figure 9 for Figure 5A partial structural diagram of the battery cell in some embodiments;

[0041] Figure 10 for Figure 5 Enlarged views of part B in some embodiments;

[0042] Figure 11 for Figure 5 Enlarged view of part B in some other embodiments;

[0043] Figure 12 A partial structural schematic diagram of the light-facing surface of the battery cell provided in this application in some embodiments;

[0044] Figure 13 A partial structural schematic diagram of the light-facing surface of the solar cell provided in this application in some other embodiments;

[0045] Figure 14 A partial structural schematic diagram of the backlight surface of the battery cell provided in this application in some embodiments;

[0046] Figure 15 for Figure 5 Enlarged view of part C in some embodiments;

[0047] Figure 16 for Figure 5 Enlarged view of part C in some other embodiments;

[0048] Figure 17 for Figure 5 Enlarged view of part D in some embodiments;

[0049] Figure 18 for Figure 5 Enlarged view of part C in some other embodiments;

[0050] Figure 19 A partial structural diagram of the battery cell provided in this application in some other embodiments;

[0051] Figure 20 for Figure 19 Enlarged view of part E in some embodiments;

[0052] Figure 21 These are structural cross-sectional views of the photovoltaic module provided in this application in some embodiments;

[0053] Figure 22 for Figure 21 A schematic diagram of the connection structure of the battery layer in some embodiments;

[0054] Figure 23 for Figure 21The diagram shows the connection structure of the battery layer in some embodiments.

[0055] Figure label:

[0056] 10-Cover plate; 101-First cover plate; 102-Second cover plate; 20-Encapsulation layer; 201-First adhesive film; 202-Second adhesive film; 30-Battery layer; 301-Battery cell; 302-Welding ribbon; 303-Busbar; 304-Complete battery cell; 305-Two-cell battery cell; 306-Three-cell battery cell;

[0057] 1-Body; 11-First edge; 12-Second edge;

[0058] 2-Pad; 21-Edge Pad; 211-First Edge Pad; 212-Second Edge Pad; 22-Center Pad; 221-Main Pad; 222-Sub-Pad; 23-Pad Row;

[0059] 3-Harpoon structure; 31-First busbar; 32-Second busbar; 33-Harpoon gap;

[0060] 4-Fine grid; 41-First fine grid; 411-First segment; 412-Second segment; 42-Second fine grid; 43-Third fine grid; 431-Third segment; 432-Fourth segment; 44-Fourth fine grid; 45-Fifth fine grid; 451-Fifth segment; 452-Sixth segment; 46-Edge fine grid; 47-Middle fine grid; 48-Main fine grid; 49-Secondary fine grid;

[0061] 5 - Main gate; X - Second direction; Y - First direction; Z - Third direction. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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%.

[0068] 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.

[0069] 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.

[0070] For an IBC cell, along its thickness direction, it sequentially includes a silicon nitride anti-reflection 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 anti-reflection 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.

[0071] 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.

[0072] The following discussion uses TOPCon batteries as an example to illustrate the specific structure of battery cells.

[0073] 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 304. In this case, the first edge 11 and the second edge 12 of the battery cell are both uncut edges, and chamfers are provided at both the first edge 11 and the second edge 12.

[0074] 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 305, that is, the entire battery cell 304 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 305. At this time, one of the first edge 11 and the second edge 12 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.

[0075] 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 306 or other multi-cell battery. Taking the three-cell battery 306 as an example, the entire battery cell 304 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 306. In this case, one of the first edge 11 and the second edge 12 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 have a chamfer. Alternatively, both the first edge 11 and the second edge 12 are cut edges, and neither the first edge 11 nor the second edge 12 has a chamfer.

[0076] The embodiments of this application do not impose any special limitation on the specific type of battery cell, that is, the battery cell can be a whole cell, a two-cell cell, a three-cell cell, or other multi-cell cell.

[0077] Figure 4 This is a partial structural diagram of a battery cell in some embodiments. Figure 4 The example shows a single, whole cell, with the first edge 11 and the second edge 12 of the cell being uncut edges.

[0078] Figure 5 This is a partial structural diagram of a battery cell in some embodiments. Figure 5 The example shows a two-piece battery cell, with the first edge 11 being a cut edge and the second edge 12 being an uncut edge.

[0079] The following discussion uses a two-cell battery as an example to illustrate the specific structure of the battery cell.

[0080] like Figure 5 As shown, the battery cell includes a body 1, 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 body 1 facing the sunlight when the back contact battery is in the working state, and the back-lighting surface is the side of the body 1 away from the sunlight when the back contact battery is in the working state. Alternatively, the light-facing surface can be understood as the upper surface of the body 1, and the back-lighting surface can be understood as the lower surface of the body 1.

[0081] like Figure 5 As shown, both the light-facing surface and the back-light-facing surface of the body 1 are provided with fine grids 4 extending along the second direction X. Multiple fine grids 4 are arranged along the first direction Y, and the fine grids 4 on the light-facing surface and the fine grids 4 on the back-light-facing surface have opposite polarities. For example, the fine grids 4 on the light-facing surface are positive fine grids, and the fine grids 4 on the back-light-facing surface are negative fine grids.

[0082] Wherein, the first direction Y and the second direction X are both perpendicular to the thickness direction of the body 1. For example, one of the first direction Y and the second direction X is the length direction of the body 1 and the other is the width direction of the body 1. The thickness direction of the body 1 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.

[0083] like Figure 5 As shown, the main body 1 is also provided with solder pads 2, which are used to weld and fix the battery to the solder ribbon. The solder ribbon is used to realize the electrical connection between adjacent battery cells and to output the current of the battery cells. The solder pads 2 are also used to electrically connect to the fine grid 4. The current on the fine grid 4 can be transmitted to the solder ribbon through the solder pads 2, thereby realizing the collection and transmission of the current on the battery cells.

[0084] like Figure 5 As shown, multiple solder pads 2 are arranged along the first direction Y, that is, a solder ribbon is welded and fixed to the solar cell through multiple solder pads 2, so as to improve the pull-out force between the solder ribbon 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 solder ribbon and the solar cell, thereby improving the performance of the solar cell.

[0085] When the solar cell is a gridless solar cell, the pad 2 is set on the fine grid 4, that is, there is a direct electrical connection between the fine grid 4 and the pad 2.

[0086] When the solar cell is a solar cell with a main grid, the pad 2 is set on the main grid 5, and the fine grid 4 is electrically connected to the main grid 5, that is, the fine grid 4 and the pad 2 are indirectly electrically connected through the main grid 5.

[0087] In addition, when the solar cell is a solar cell with a main grid, the pad 2 is set on the main grid 5, and the fine grid 4 can also be directly electrically connected to the pad 2.

[0088] This application does not specifically limit the type of solar cell in its embodiments. For ease of description, the specific structure of the solar cell will be discussed in detail below using a gridless solar cell as an example.

[0089] like Figure 5 As shown, the body 1 also includes a first edge 11 and a second edge 12 distributed along the first direction Y.

[0090] like Figure 5 As shown, multiple pads 2 are arranged along the first direction Y. The pad 2 located on the outermost side of the first direction Y is denoted as edge pad 21, and the pad 2 between two edge pads 21 is denoted as middle pad 22. That is, in the first direction Y, the middle pad 22 is located on one side of the edge pad 21.

[0091] like Figure 5 As shown, at least one of the light-facing surface and the backlight surface is provided with a harpoon structure 3, and in the first direction Y, the harpoon structure 3 is located on the side of the edge pad 21 away from the middle pad 22.

[0092] Figure 6 for Figure 5 The enlarged structural view of part A in some embodiments is shown. For example... Figure 6As shown, the harpoon structure 3 includes a first busbar 31 and a second busbar 32. Both the first busbar 31 and the second busbar 32 are connected to the edge pad 21. The first busbar 31 and the second busbar 32 have a harpoon gap 33 in the second direction X.

[0093] The extension direction of the first busbar 31 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. In this embodiment, the extension direction of the first busbar 31 is not specifically limited.

[0094] The extension direction of the second busbar 32 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. In this embodiment, the extension direction of the second busbar 32 is not specifically limited.

[0095] The first bus 31 and the second bus 32 can be symmetrically arranged on both sides of the edge pad 21, or they can be arranged asymmetrically. The present application embodiment does not impose any special limitation on the distribution of the first bus 31 and the second bus 32.

[0096] Taking the side where the first edge 11 is located as an example, such as Figure 6 As shown, the fine gate 4 includes a first fine gate 41 and a second fine gate 42. In the first direction Y, both the first fine gate 41 and the second fine gate 42 are located on the side of the edge pad 21 away from the middle pad 22. The first fine gate 41 is located between the second fine gate 42 and the edge pad 21.

[0097] like Figure 6 As shown, the first fine grid 41 is connected to the first busbar 31 and the second busbar 32 respectively, and the first fine grid 41 is broken at the harpoon gap 33 to form a first segment 411 and a second segment 412 arranged along the second direction X. The first segment 411 is electrically connected to the first busbar 31, and the second segment 412 is electrically connected to the second busbar 32.

[0098] like Figure 6 As shown, the second fine grid 42 is connected to the first busbar 31 and the second busbar 32 respectively, and the second fine grid 42 passes through the harpoon gap 33 along the second direction.

[0099] In this embodiment, the current on the first fine grid 41 and the second fine grid 42 can be transmitted to the edge pad 21 through the first busbar 31 and the second busbar 32, and then transmitted to the solder ribbon through the edge pad 21, so as to realize the collection and transmission of the current on the first fine grid 41 and the second fine grid 42, improve the current collection efficiency at the edge of the cell, and thus improve the output power of the cell.

[0100] In this embodiment, the first fine grid 41 is broken at the harpoon structure 3, which reduces the amount of paste required for the first fine grid 41, thereby reducing the material cost of the first fine grid 41 and thus helping to reduce the cost of the battery cell.

[0101] In this embodiment, the second fine grid 42 penetrates the harpoon structure 3, meaning that the second fine grid 42 is not broken at the harpoon structure 3. This optimizes the current collection path, helps reduce current transmission loss, and thus improves the output power of the solar cell.

[0102] The number of first fine grids 41 can be one or more, that is, the number of first fine grids 41 arranged in the first direction Y is N1, where 1≤N1≤10. The number of first fine grids 41 here refers to the number of arrangement on one side of the battery cell. For example, on the side where the first edge of the battery cell is located, that is, between the edge pad 21 and the first edge 11, the number of first fine grids 41 is one or more.

[0103] For example, the number of first fine gates 41 arranged in the first direction Y between the edge pad 21 and the first edge 11 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0104] When there are multiple first fine gates 41, all of the multiple first fine gates 41 are located on the side of the second fine gate 42 facing the edge pad 21.

[0105] The number of second fine grids 42 can be one or more. The number of second fine grids 42 here refers to the number of grids on one side of the battery cell. For example, on the side where the first edge of the battery cell is located, that is, between the edge pad 21 and the first edge 11, the number of second fine grids 42 is one or more.

[0106] When there are multiple second fine gates 42, all of the multiple second fine gates 42 are located on the side of the first fine gate 41 away from the edge pad 21.

[0107] In some embodiments, such as Figure 6 As shown, taking the first edge 11 as an example, the fine gate 4 closest to the first edge 11 between the edge pad 21 and the first edge 11 is constructed as the second fine gate 42 that penetrates the harpoon structure 3. The fine gate 4 located on the outermost side in the first direction Y is denoted as the edge fine gate, and the second fine gate 42 is constructed as the edge fine gate.

[0108] In this embodiment, the second fine grid 42 is located on the outermost side, which improves the current collection efficiency at the edge of the cell, thereby improving the brightness uniformity of the cell EL test, reducing the risk of local failure after cell aging, and thus improving the output power of the cell.

[0109] Figure 7 for Figure 5 The diagram shows an enlarged view of part A in some other embodiments. In other embodiments, such as... Figure 7 As shown, the fine gate 4 also includes a third fine gate 43, which is located on the side of the second fine gate 42 away from the first fine gate 41 in the first direction Y.

[0110] The third fine grid 43 is connected to the first busbar 31 and the second busbar 32 respectively. The third fine grid 43 is broken at the harpoon gap 33 to form a third segment 431 and a fourth segment 432 distributed along the second direction X. The third segment 431 is electrically connected to the first busbar 31, and the fourth segment 432 is electrically connected to the second busbar 32.

[0111] Taking the first edge 11 as an example, such as Figure 7 As shown, the fine gate 4 closest to the first edge 11 is constructed as a broken third fine gate 43. The fine gate 4 located on the outermost side in the first direction Y is denoted as the edge fine gate, and the third fine gate 43 is constructed as the edge fine gate.

[0112] In this embodiment, the third fine grid 43 is broken at the harpoon structure 3, which reduces the amount of paste required for the third fine grid 43, thereby reducing the material cost of the third fine grid 43 and thus helping to reduce the cost of the solar cell.

[0113] In this embodiment, the edge grid is broken at the harpoon structure 3, which can optimize the current collection path at the edge of the cell and reduce current transmission loss, thereby helping to improve the output power of the cell.

[0114] The number of third fine grids 43 can be one or more, that is, the number of third fine grids 43 arranged in the first direction Y is N2, where 1≤N2≤10. The number of third fine grids 43 here refers to the number of arrangement on one side of the solar cell. For example, on the side where the first edge of the solar cell is located, that is, between the edge pad 21 and the first edge 11, the number of third fine grids 43 is one or more.

[0115] For example, the number of third fine gates 43 arranged in the first direction Y between the edge pad 21 and the first edge 11 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0116] When there are multiple third fine gates 43, all of the multiple third fine gates 43 are located on the side of the second fine gate 42 away from the edge pad 21.

[0117] In some embodiments, such as Figure 7As shown, the end of the first segment 411 facing the second segment 412 is connected to the first busbar 31, and the end of the second segment 412 facing the first segment 411 is connected to the second busbar 32, so as to reduce the length of the first fine gate 41 and thus reduce the material cost of the first fine gate 41.

[0118] Figure 8 for Figure 5 The enlarged structural view of part A in some embodiments. In other embodiments, such as Figure 8 As shown, the first segment 411 is connected to the first busbar 31 and extends along the second direction X into the harpoon gap 33. The second segment 412 is connected to the second busbar 32 and extends along the second direction X into the harpoon gap 33, so as to increase the length of the first fine grid 41 and improve the current collection efficiency of the first fine grid 41.

[0119] In some embodiments, such as Figure 7 As shown, the end of the third segment 431 facing the fourth segment 432 is connected to the first busbar 31, and the end of the fourth segment 432 facing the third segment 431 is connected to the second busbar 32, so as to reduce the length of the third fine gate 43 and thus reduce the material cost of the third fine gate 43.

[0120] In other embodiments, such as Figure 8 As shown, the third segment 431 is connected to the first busbar 31 and extends along the second direction X into the harpoon gap 33. The fourth segment 432 is connected to the second busbar 32 and extends along the second direction X into the harpoon gap 33 to increase the length of the third fine grid 43 and improve the current collection efficiency of the third fine grid 43.

[0121] The fine grating 4 structure at the first edge 11 and the fine grating 4 structure at the second edge 12 can be the same or different.

[0122] Figure 9 for Figure 5 The diagram shows a partial structural representation of the battery cell in some embodiments. For example... Figure 9 As shown, the edge pad 21 includes a first edge pad 211 and a second edge pad 212 arranged along the first direction Y. In the first direction Y, the first edge pad 211 is located between the first edge 11 and the second edge pad 212.

[0123] In the first direction Y, a harpoon structure 3 is provided between the first edge pad 211 and the first edge 11, and between the second edge pad 212 and the second edge 12.

[0124] When the fine gate 4 structure at the first edge 11 is the same as the fine gate 4 structure at the second edge 12, the first fine gate 41 and the second fine gate 42 described above are provided between the first edge pad 211 and the first edge 11, and the first fine gate 41 and the second fine gate 42 described above are provided between the second edge pad 212 and the second edge 12.

[0125] Alternatively, when the fine grating 4 structure at the first edge 11 is the same as the fine grating 4 structure at the second edge 12, such as... Figure 9 As shown, the first fine gate 41, the second fine gate 42 and the third fine gate 43 are provided between the first edge pad 211 and the first edge 11, and the first fine gate 41, the second fine gate 42 and the third fine gate 43 are provided between the second edge pad 212 and the second edge 12.

[0126] When the fine gate structure 4 at the first edge 11 is different from the fine gate structure 4 at the second edge 12, the fine gate structure 4 at the first edge 11 can be as follows: Figures 6 to 8 As shown, the first fine gate 41 and the second fine gate 42 are provided between the first edge pad 211 and the first edge 11, or the first fine gate 41, the second fine gate 42 and the third fine gate 43 are provided between the first edge pad 211 and the first edge 11.

[0127] When the fine gate 4 structure at the first edge 11 is different from the fine gate 4 structure at the second edge 12, several possible designs of the fine gate 4 structure at the second edge 12 will be discussed in detail below.

[0128] Figure 10 for Figure 5 Part B in the diagram is an enlarged view in some embodiments. For example... Figure 10 As shown, the fine gate 4 also includes a fourth fine gate 44. In the first direction Y, the fourth fine gate 44 is located between the second edge pad 212 and the second edge 12. The fourth fine gate 44 is connected to the first busbar 31 and the second busbar 32 respectively, and the fourth fine gate 44 penetrates the harpoon gap 33 along the second direction.

[0129] In this embodiment, the fourth fine grid 44 penetrates through the harpoon structure 3, meaning that the fourth fine grid 44 is not broken at the harpoon structure 3. This optimizes the current collection path, helps reduce current transmission loss, and thus improves the output power of the solar cell.

[0130] In some embodiments, such as Figure 10 As shown, the outermost fine grid 4 in the first direction Y is denoted as the edge fine grid, and the fourth fine grid 44 is constructed as the edge fine grid.

[0131] In this embodiment, the fourth fine grid 44 is located on the outermost side, which improves the current collection efficiency at the second edge 12 of the cell, thereby improving the brightness uniformity of the cell EL test, reducing the risk of local failure after cell aging, and thus improving the output power of the cell.

[0132] Figure 11 for Figure 5 Enlarged views of part B in other embodiments. For example... Figure 11 As shown, the fine grid 4 also includes a fifth fine grid 45. In the first direction Y, the fifth fine grid 45 is located between the fourth fine grid 44 and the second edge 12. The fifth fine grid 45 is connected to the first confluence portion 31 and the second confluence portion 32 respectively. The fifth fine grid 45 is broken at the harpoon gap 33 to form a fifth segment 451 and a sixth segment 452 arranged along the second direction X.

[0133] If the outermost fine grid 4 in the first direction Y is designated as the edge fine grid, then the fifth fine grid 45 is constructed as the edge fine grid.

[0134] In this embodiment, the fifth fine grid 45 is broken at the harpoon structure 3, which reduces the amount of paste required for the fifth fine grid 45, thereby reducing the material cost of the fifth fine grid 45 and thus helping to reduce the cost of the solar cell.

[0135] In this embodiment, the edge grid is broken at the harpoon structure 3, which can optimize the current collection path at the edge of the cell and reduce current transmission loss, thereby helping to improve the output power of the cell.

[0136] The number of fifth fine grids 45 can be one or more, that is, the number of fifth fine grids 45 arranged in the first direction Y is N3, where 1≤N3≤10. The number of fifth fine grids 45 here refers to the number of arrangement on one side of the solar cell. For example, on the side where the first edge of the solar cell is located, that is, between the second edge pad 212 and the second edge 12, the number of fifth fine grids 45 is one or more.

[0137] For example, between the second edge pad 212 and the second edge 12, the number of fifth fine gates 45 arranged in the first direction Y can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0138] When there are multiple fifth fine gates 45, all of the fifth fine gates 45 are located on the side of the fourth fine gate 44 away from the second edge pad 212.

[0139] The number of fourth fine gates 44 can be one or more. When there are multiple fourth fine gates 44, all of them are located on the side of the fifth fine gate 45 facing the second edge pad 212.

[0140] In some embodiments, such as Figure 11 As shown, the end of the fifth segment 451 facing the sixth segment 452 is connected to the first busbar 31, and the end of the sixth segment 452 facing the fifth segment 451 is connected to the second busbar 32, so as to reduce the length of the first fine grid 41 and thus reduce the material cost of the first fine grid 41.

[0141] In other embodiments, the fifth segment 451 is connected to the first busbar 31 and extends along the second direction X into the harpoon gap 33, and the sixth segment 452 is connected to the second busbar 32 and extends along the second direction X into the harpoon gap 33, so as to increase the length of the fifth fine gate 45 and improve the current collection efficiency of the fifth fine gate 45.

[0142] Based on the aforementioned fine grating 4 structure, on the light-facing surface of the body 1, the fine grating 4 structure at the first edge 11 and the fine grating 4 structure at the second edge 12 can be the same or different. On the backlighting surface of the body 1, the fine grating 4 structure at the first edge 11 and the fine grating 4 structure at the second edge 12 can be the same or different. The fine grating 4 structure on the light-facing surface of the body 1 and the fine grating 4 structure on the backlighting surface can be the same or different.

[0143] Figure 12 This is a partial structural schematic diagram of the light-facing surface of the battery cell provided in this application in some embodiments. Figure 12 An example is shown where, on the light-facing surface of the body 1, the fine gate 4 structure at the first edge 11 is the same as the fine gate 4 structure at the second edge 12. A harpoon structure 3, a broken first fine gate 41, and a through second fine gate 42 are provided between the first edge pad 211 and the first edge 11. A harpoon structure 3, a broken first fine gate 41, and a through second fine gate 42 are provided between the second edge pad 212 and the second edge 12.

[0144] Figure 13 This is a partial structural diagram of the light-facing surface of the battery cell provided in this application in some other embodiments. Figure 13 An example is shown where the fine gate 4 structure at the first edge 11 on the light-facing surface of the body 1 is different from the fine gate 4 structure at the second edge 12. A harpoon structure 3, a broken first fine gate 41, and a through second fine gate 42 are provided between the first edge pad 211 and the first edge 11. The second fine gate 42 is constructed as the edge fine gate 46 at the first edge 11. A harpoon structure 3, a through fourth fine gate 44, and a broken fifth fine gate 45 are provided between the second edge pad 212 and the second edge 12. The fifth fine gate 45 is constructed as the edge fine gate 46 at the second edge 12.

[0145] Figure 14 This application provides partial structural schematic diagrams of the backlight surface of the battery cell in some embodiments. See also: Figure 12 and Figure 14 Or, refer to at the same time Figure 13 and Figure 14 , Figure 14 The example illustrates that the fine grating 4 structure on the light-facing surface of the body 1 differs from the fine grating 4 structure on the back-facing surface. Figure 14 An example is shown where the fine gate 4 structure at the first edge 11 on the backlight surface of the body 1 is different from the fine gate 4 structure at the second edge 12. A harpoon structure 3, a broken first fine gate 41, a through second fine gate 42 and a broken third fine gate 43 are provided between the first edge pad 211 and the first edge 11. The third fine gate 43 is constructed as the edge fine gate 46 at the first edge 11. A harpoon structure 3 and a through fourth fine gate 44 are provided between the second edge pad 212 and the second edge 12. The fourth fine gate 44 is constructed as the edge fine gate 46 at the second edge 12.

[0146] Based on the aforementioned battery cell, the pull-out force between the solder ribbon and the battery cell can be increased by adjusting the structure and arrangement of the solder pad 2. The structural design of the solder pad 2 is discussed in detail below.

[0147] Figure 15 for Figure 5 Enlarged views of part C in some embodiments. For example... Figure 15 As shown, the pad 2 located on the outermost side in the first direction Y is denoted as edge pad 21, and the pad 2 between the two edge pads 21 is denoted as middle pad 22.

[0148] like Figure 15 As shown, the central pad 22 includes a main pad 221 and a secondary pad 222. In the third direction Z, the projected area of ​​the main pad 221 is larger than the projected area of ​​the secondary pad 222. Multiple main pads 221 are arranged along the first direction Y, and at least two secondary pads 222 are included between two adjacent main pads 221.

[0149] In this embodiment, the area of ​​the main pad 221 is larger than the area of ​​the secondary pad 222, so that the welding area between the main pad 221 and the solder strip is larger than the welding area between the secondary pad 222 and the solder strip, thereby increasing the pull-out force between the solder strip and the cell, reducing the risk of the solder strip detaching from the cell, and improving the anti-aging ability and performance of the cell.

[0150] The large welding area between the main pad 221 and the solder strip enhances the current transmission capability between the main pad 221 and the solder strip, thereby improving the solder strip's current collection capability and thus increasing the output power of the solar cell.

[0151] By setting up a larger main pad 221 and a smaller secondary pad 222, the pull-out force between the solder ribbon and the cell and the current transmission capability can be improved, while the amount of paste required for the pad 2 can be reduced, thereby reducing the cost of the pad 2 and the cell.

[0152] The width of the main pad 221 in the second direction X is W1, and the width of the secondary pad 222 in the second direction X is W2, where W2 < W1.

[0153] In this embodiment, under the premise that the area of ​​the main pad 221 is greater than the area of ​​the sub-pad 222, W2 < W1, which can reduce the distance between the fine gate connected to the main pad 221 and the fine gate connected to the sub-pad 222 in the first direction Y, which is beneficial to increase the number of fine gates in the first direction Y and improve the output power of the battery cell.

[0154] 1mm≤W1≤3.5mm. For example, the width of the main pad 221 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.

[0155] If the width of the main pad 221 in the second direction X is small, and the distance between the fine grid connected to the main pad 221 and the fine grid connected to the sub-pad 222 in the first direction Y is a preset value, that is, when the size of the main pad 221 in the first direction Y is a preset value, then the welding area between the main pad 221 and the solder strip is small, and the pull-out force between the solder strip and the cell is small.

[0156] If the width of the main pad 221 in the second direction X is small, and the area of ​​the main pad 221 is a preset value, then the size of the main pad 221 in the first direction Y is large. When the distance between the main pad 221 and the sub-pad 222 in the first direction Y is a preset value, then the distance between the fine gate connected to the main pad 221 and the fine gate connected to the sub-pad 222 in the first direction Y is large, and the number of fine gates in the first direction Y is small, which affects the output power of the battery cell.

[0157] If the width of the main pad 221 in the second direction X is large, and the width of the solder strip in the second direction X is a preset value, and the area of ​​the main pad 221 is a preset value, the size of the main pad 221 in the first direction Y is small. Then the welding area of ​​the main pad 221 and the auxiliary pad 222 with the solder strip is small, and the pull-out force between the solder strip and the cell is small.

[0158] If the width of the main pad 221 in the second direction X is large, and the contact area between the main pad 221 and the solder strip is a preset value, then the area of ​​the main pad 221 is large, which makes the material cost of the main pad 221 higher.

[0159] Therefore, 1mm≤W1≤3.5mm can increase the welding area between the main pad 221 and the solder ribbon, thereby increasing the pull-out force of the solder ribbon on the cell. It can also reduce the material cost of the main pad 221 and increase the number of fine grids to improve the output power of the cell.

[0160] For example, 1mm≤W1≤1.5mm, the width of the main pad 221 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.

[0161] For example, 1.5mm≤W1≤2mm, the width of the main pad 221 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.

[0162] For example, 2mm≤W1≤2.5mm, the width of the main pad 221 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.

[0163] For example, 2.5mm≤W1≤3mm, the width of the main pad 221 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.

[0164] For example, 3mm≤W1≤3.5mm, the width of the main pad 221 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.

[0165] 0.3mm≤W2≤1.2mm. For example, the width of the sub-pad 222 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.

[0166] If the width of the sub-pad 222 in the second direction X is small, and the distance between the fine grid connected to the main pad 221 and the fine grid connected to the sub-pad 222 in the first direction Y is a preset value, that is, when the size of the sub-pad 222 in the first direction Y is a preset value, then the welding area between the sub-pad 222 and the solder strip is small, and the pull-out force between the solder strip and the cell is small.

[0167] If the width of the sub-pad 222 in the second direction X is small, and the area of ​​the sub-pad 222 is a preset value, then the size of the sub-pad 222 in the first direction Y is large. When the distance between the sub-pad 222 and the main pad 221 in the first direction Y is a preset value, then the distance between the fine grid connected to the main pad 221 and the fine grid connected to the sub-pad 222 in the first direction Y is large, and the number of fine grids in the first direction Y is small, which affects the output power of the battery cell.

[0168] If the width of the sub-pad 222 in the second direction X is large, and the width of the solder strip in the second direction X is a preset value, and the area of ​​the sub-pad 222 is a preset value, the size of the sub-pad 222 in the first direction Y will be small. Then the welding area of ​​the main pad 221 and the sub-pad 222 with the solder strip will be small, and the pull-out force between the solder strip and the cell will be small.

[0169] If the width of the sub-pad 222 in the second direction X is large, and the contact area between the sub-pad 222 and the solder strip is a preset value, then the area of ​​the sub-pad 222 is large, which makes the material cost of the sub-pad 222 higher.

[0170] Therefore, 0.3mm≤W2≤1.2mm can increase the welding area between the sub-pad 222 and the solder ribbon, thereby increasing the pull-out force of the solder ribbon on the cell. It can also reduce the material cost of the sub-pad 222 and increase the number of fine grids to improve the output power of the cell.

[0171] For example, 0.3mm≤W2≤0.6mm, the width of the sub-pad 222 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.

[0172] For example, 0.6mm≤W2≤0.9mm, the width of the sub-pad 222 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.

[0173] For example, 0.9mm≤W2≤1.2mm, the width of the sub-pad 222 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.

[0174] In some embodiments, on the third-party direction Z, the projected area of ​​the edge pad 21 is equal to the projected area of ​​the main pad 221.

[0175] In other implementations, on the third-party Z-axis, the projected area of ​​the edge pad 21 is larger than the projected area of ​​the main pad 221 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 and reducing the risk of the solder strip detaching from the cell, thus improving the cell's anti-aging ability and cell performance.

[0176] like Figure 15 As shown, in the first direction Y, at least three sub-pads 222 are included between the edge pad 21 and the adjacent main pad 221 to increase the pull-out force of the solder ribbon at the edge of the cell, reduce the risk of the solder ribbon detaching from the cell, and improve the anti-aging ability and performance of the cell.

[0177] The edge pad 21 and the adjacent main pad 221 include at least three sub-pads 222. While meeting the pull-out force of the solder strip at the edge of the cell, the material cost of the pad 2 can be reduced, thereby reducing the cost of the cell.

[0178] The outline shape of the pad 2 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 pad 2.

[0179] Figure 16 for Figure 5 The enlarged view of part C in some embodiments. In some embodiments, the outline shape of the main pad 221 is circular or rectangular, and the outline shape of the sub-pad 222 is T-shaped, I-shaped, or Z-shaped.

[0180] In this embodiment, the outline of the main pad 221 is circular or rectangular to increase the area of ​​the main pad 221 and improve the current transmission efficiency and pull-out force between the main pad 221 and the solder strip.

[0181] The outline shape of the sub-pad 222 is T-shaped, I-shaped or Z-shaped. Under the premise that the area of ​​the sub-pad 222 is small, it can increase and improve the welding stress between the sub-pad 222 and the solder 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.

[0182] In some embodiments, such as Figure 16 As shown, the number of pads 2 and fine grids 4 in the first direction Y is the same, that is, the number of fine grids 4 between two adjacent pads 2 is 0, so that each fine grid 4 is electrically connected to the solder strip through the pad 2. This increases the number of pads 2, improves the pull force between the pads 2 and the cell, and also improves the current collection efficiency of the solder strip on the cell, thereby improving the output power of the cell.

[0183] Figure 17 for Figure 5 Enlarged view of part D in some embodiments. In other embodiments, such as Figure 17 As shown, in the first direction Y, at least one fine grid 4 is included between two adjacent pads 2 to reduce the number of pads 2, thereby reducing the material cost of the pads 2 and thus reducing the cost of the battery cell.

[0184] Among them, such as Figure 17 As shown, the pads 2 and the grid 4 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 cell or solder strip damage caused by stress concentration.

[0185] Figure 18 for Figure 5 The enlarged view of part C in some embodiments. When the number of fine gates 4 between two adjacent pads 2 is 0, as shown... Figure 18 As shown, the fine gate 4 includes a main fine gate 48 and a secondary fine gate 49. The end of the main fine gate 48 contacts the main pad 221, and the end of the secondary fine gate 49 contacts the secondary pad 222. In the first direction Y, the distance between the main fine gate 48 and its adjacent secondary fine gate 49 is L1, and the distance between two adjacent secondary fine gates 49 is L2, where 0.3 ≤ L1 / L2 ≤ 7. For example, the ratio of L1 to L2 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.

[0186] For example, 0.3≤L1 / L2≤1, and the ratio of L1 to L2 can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0187] For example, 1≤L1 / L2≤3, and the ratio of L1 to L2 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.

[0188] For example, 3≤L1 / L2≤5, and the ratio of L1 to L2 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.

[0189] For example, 5≤L1 / L2≤7, and the ratio of L1 to L2 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.

[0190] And L2 < L1.

[0191] In this embodiment, the distance between the main fine grid 48 and its adjacent sub-fine grid 49 is relatively large, while the distance between two adjacent sub-fine grids 49 is relatively small. This results in a larger spacing between the main pad 221 and its adjacent sub-pad 222, and a smaller spacing between adjacent sub-pads 222. This reduces the risk of contact between the main pad 221 and its adjacent sub-pad 222, thereby reducing the risk of reduced cell efficiency due to a large surface area of ​​the cell being obscured, and thus improving the cell's output power. Simultaneously, the smaller spacing between adjacent sub-pads 222 allows for an increase in the number of sub-pads 222, which in turn improves the pull-out force between the solder ribbon and the cell, thus enhancing the cell's anti-aging performance.

[0192] 0.5mm≤L1≤2mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0193] If the distance between the main fine grid 48 and its adjacent sub-fine grid 49 is small, the risk of the main pad 221 and its adjacent sub-pad 222 coming into contact is high, which increases the risk of the cell's shading area and affects the cell's output power.

[0194] If the distance between the main fine grid 48 and its adjacent secondary fine grid 49 is small, the number of fine grids 4 will be large, resulting in a higher cost for the solar cell.

[0195] If the distance between the main fine grid 48 and its adjacent secondary fine grid 49 is large, the number of pads 2 will be small, affecting the pull-out force between the solder ribbon and the cell, thus improving the anti-aging performance of the cell.

[0196] If the distance between the main fine grid 48 and its adjacent secondary fine grid 49 is large, the number of fine grids 4 will be small, resulting in lower current collection efficiency of the solar cell and affecting the output power of the solar cell.

[0197] Therefore, a thickness of 0.5mm ≤ L1 ≤ 2mm can reduce the shading area of ​​the solar cell by the solder pad 2, thereby increasing the output power of the solar cell. Simultaneously, it can increase the number of solder pads 2, thereby increasing the pull-out force between the solder ribbon and the solar cell, thus improving the anti-aging performance of the solar cell. Furthermore, it can increase the output power of the solar cell while reducing its material cost.

[0198] For example, 0.5mm≤L1≤0.7mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0199] For example, 0.7mm≤L1≤0.9mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0200] For example, 0.9mm≤L1≤1.1mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0201] For example, 1.1mm≤L1≤1.3mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0202] For example, 1.3mm≤L1≤1.5mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0203] For example, 1.5mm≤L1≤1.7mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0204] For example, 1.7mm≤L1≤1.9mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0205] For example, 1.9mm≤L1≤2mm, the distance between the main fine grid 48 and its adjacent secondary fine grid 49 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.

[0206] 0.3mm≤L2≤1.5mm, the distance between two adjacent sub-fine grids 49 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.

[0207] If the distance between two adjacent sub-grids 49 is small, the risk of contact between the two adjacent sub-pads 222 is greater, which increases the risk of increased shading area of ​​the solar cell and affects the output power of the solar cell.

[0208] If the distance between two adjacent sub-grids 49 is small, the number of grids 4 will be large, resulting in a higher cost for the solar cell.

[0209] If the distance between two adjacent sub-grids 49 is large, the number of pads 2 will be small, affecting the pull-out force between the solder ribbon and the cell, thus improving the anti-aging performance of the cell.

[0210] If the distance between two adjacent sub-grids 49 is large, the number of grids 4 will be small, resulting in lower current collection efficiency of the solar cell and affecting the output power of the solar cell.

[0211] Therefore, a thickness of 0.3mm ≤ L2 ≤ 1.5mm can reduce the area of ​​the solar cell obstructed by the solder pad 2, thereby increasing the output power of the solar cell. Simultaneously, it can increase the number of solder pads 2 to improve the pull-out force between the solder ribbon and the solar cell, thus enhancing the anti-aging performance of the solar cell. Furthermore, it can increase the output power of the solar cell while reducing its material cost.

[0212] For example, 0.3mm≤L2≤0.5mm, the distance between two adjacent sub-fine grids 49 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.

[0213] For example, 0.5mm≤L2≤0.7mm, the distance between two adjacent sub-grids 49 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.

[0214] For example, 0.7mm≤L2≤0.9mm, the distance between two adjacent sub-fine grids 49 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.

[0215] For example, 0.9mm≤L2≤1.1mm, the distance between two adjacent sub-fine grids 49 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.

[0216] For example, 1.1mm≤L2≤1.3mm, the distance between two adjacent sub-fine grids 49 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.

[0217] For example, 1.3mm≤L2≤1.5mm, the distance between two adjacent sub-fine grids 49 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.

[0218] The solar cells can be either gridless or grid-connected.

[0219] When the solar cell is a gridless solar cell, Figure 18 Taking the structure shown as an example, the pad 2 is directly connected to the grid 4 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.

[0220] Figure 19This is a partial structural diagram of a battery cell in some embodiments. Figure 20 for Figure 19 An enlarged view of the structure of part E in the diagram. When the solar cell is a cell with a main busbar, as shown... Figure 19 and Figure 20 As shown, the solar cell also includes a main grid 5 extending along a first direction Y, with fine grids 4 connected to the main grid 5, and at least a portion of the pads 2 located on the main grid 5. In this case, the fine grids 4 and the pads 2 can be indirectly electrically connected through the main grid 5, or they can be directly electrically connected.

[0221] like Figure 19 As shown, multiple main gates 5 are arranged at intervals along the second direction X. The number of main gates 5 in the second direction X is N4, where 5≤N4≤24. The number of main gates 5 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.

[0222] If the number of main grids 5 is small, the current collection efficiency is low, and the length of the fine grids 4 in the second direction Y is extended, thereby increasing the resistance in the current transmission process and affecting the output power of the solar cell.

[0223] If there are many main grids 5, the main grids 5 will block a large area of ​​the solar cells, which will affect the output power of the solar cells and increase the cost of the solar cell paste.

[0224] Therefore, 5≤N4≤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 grid 5 on the solar cell, which helps to improve the output power of the solar cell and reduce the material cost of the solar cell.

[0225] like Figure 19 As shown, pads 2 arranged along the first direction Y form a pad column 23, and multiple pad columns 23 are arranged along the second direction X.

[0226] In some embodiments, in the second direction X, the number of main grids 5 is the same as the number of pad columns 23, and the main grids 5 correspond one-to-one with the pad columns 23 to improve the current collection efficiency of the solar cell.

[0227] In other embodiments, in the second direction X, the number of main grids 5 is less than the number of pad rows 23, that is, there is at least one pad row 23 not connected to the main grid 5 between two adjacent main grids 5. While reducing the number of main grids 5, the number of solder strips is increased, thereby improving the output power of the cell.

[0228] In some embodiments, the number of main gates 5 in the first direction Y is 1, that is, in the first direction Y, all pads 2 in a pad row 23 are disposed on the same main gate 5.

[0229] In other embodiments, multiple main grids 5 are arranged at intervals along the first direction Y. That is, in the first direction Y, some pads 2 in a pad row 23 are disposed on the main grid 5, and some pads 2 are not disposed on the main grid 5, so as to reduce the material cost of the main grid 5 and reduce the shading area of ​​the main grid 5 on the solar cell, thereby improving the output power of the solar cell.

[0230] The second aspect of this application provides a photovoltaic module. Figure 21 The following are schematic diagrams of the structure of the photovoltaic module provided in this application in some embodiments, such as... Figure 21 As shown, the photovoltaic module includes a cover plate 10, an encapsulation layer 20, and a cell layer 30.

[0231] The cover plate 10 includes a first cover plate 101 and a second cover plate 102 arranged along the third direction Z. The encapsulation layer 20 and the battery layer 30 are located between the first cover plate 101 and the second cover plate 102. A portion of the encapsulation layer 20 is located between the battery layer 30 and the first cover plate 101, and another portion of the encapsulation layer 20 is located between the battery layer 30 and the second cover plate 102, so as to achieve the encapsulation and fixation of the cover plate 10 and the battery layer 30.

[0232] At least one of the first cover plate 101 and the second cover plate 102 is made of a light-transmitting material, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic module.

[0233] The first cover plate 101 can be made of one of the following rigid materials: tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the first cover plate 101 can be made of one of the following flexible materials: PVF (polyvinyl fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), or PVDF (polyvinylidene fluoride). All of these materials have high light transmittance, ensuring that more light reaches the battery layer, thereby increasing the light absorption of the photovoltaic module and improving its photoelectric conversion efficiency.

[0234] The material of the second cover plate 102 can be one of rigid materials such as tempered glass, PET (polyethylene terephthalate), or PC (polycarbonate). Alternatively, the material of the second cover plate 102 can be one of flexible materials such as PVF (polyvinyl fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), or PVDF (polyvinylidene fluoride).

[0235] The materials of the first cover plate 101 and the second cover plate 102 can be the same or different.

[0236] like Figure 21 As shown, the encapsulation layer 20 includes a first adhesive film 201 and a second adhesive film 202. In the third direction Z, a portion of the structure of the first adhesive film 201 is located between the battery layer 30 and the first cover plate 101, and a portion of the structure of the second adhesive film 202 is located between the battery layer and the second cover plate 102.

[0237] The first encapsulant film 201 is made of one of the following polyolefins: EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral). These materials have high light transmittance, which is beneficial for improving the photoelectric conversion efficiency of photovoltaic modules. The first encapsulant film 201 can also be an EPE film (EVA-POE-EVA co-extrusion structure) or an EP film (EVA-POE co-extrusion structure).

[0238] The material of the second film 202 is one of polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), and PVB (Polyvinyl Butyral). The second film 202 can also be an EPE film (EVA-POE-EVA co-extrusion structure) or an EP film (EVA-POE co-extrusion structure).

[0239] The materials of the first adhesive film 201 and the second adhesive film 202 can be the same or different.

[0240] Figure 22 This is a schematic diagram of the connection structure of the battery layer in some embodiments, such as... Figure 22As shown, the battery layer 30 includes multiple battery strings connected in series or in parallel. Each battery string is composed of multiple battery cells 301 connected in series. The battery cells 301 include, but are not limited to, monocrystalline silicon battery cells and polycrystalline silicon battery cells. Adjacent battery cells 301 are connected by solder ribbons 302. The solder ribbons 302 are soldered and fixed to the solder pads on the battery cells 301. The battery cells 301 are the aforementioned battery cells.

[0241] Figure 23 This is a schematic diagram of the battery layer structure in some embodiments, such as... Figure 23 As shown, the battery layer 30 also includes a busbar 303. Along the first direction Y, the busbar 303 is located on both sides of the battery string and is used to realize the series or parallel connection between multiple battery strings.

[0242] 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 battery cell, characterized in that, The battery cell includes: The body (1) further includes a light-facing surface and a back-light-facing surface distributed along the thickness direction of the battery cell; Pads (2), a plurality of said pads (2) are arranged along a first direction (Y), said pads (2) include an outermost edge pad (21) located in the first direction (Y), said pads (2) also include a middle pad (22) located on one side of said edge pad (21) in the first direction (Y); At least one of the light-facing surface and the backlight surface is provided with a harpoon structure (3). In the first direction (Y), the harpoon structure (3) is located on the side of the edge pad (21) away from the middle pad (22). The harpoon structure (3) includes a harpoon gap (33). A fine gate (4) extending along a second direction (X), the fine gate (4) including a first fine gate (41) and a second fine gate (42), in the first direction (Y), the first fine gate (41) and the second fine gate (42) are both located on the side of the edge pad (21) away from the central pad (22), the first fine gate (41) is located between the second fine gate (42) and the edge pad (21); Both the first fine grid (41) and the second fine grid (42) are connected to the harpoon structure (3). The first fine grid (41) is disconnected at the harpoon gap (33), and the second fine grid (42) penetrates the harpoon gap (33) along the second direction (X).

2. The battery cell according to claim 1, characterized in that, In the first direction (Y), the battery cell includes an outermost edge grid (46), and the second grid (42) is configured as the edge grid (46).

3. The battery cell according to claim 1, characterized in that, The fine grid (4) further includes a third fine grid (43), which is located on the side of the second fine grid (42) away from the first fine grid (41) in the first direction (Y); The third fine grid (43) is connected to the harpoon structure (3), and the third fine grid (43) is disconnected at the harpoon gap (33).

4. The battery cell according to claim 1, characterized in that, The body (1) includes a first edge (11) and a second edge (12) arranged along the first direction (Y), and the edge pad (21) includes a first edge pad (211) and a second edge pad (212) arranged along the first direction (Y). In the first direction (Y), the first edge pad (211) is located between the first edge (11) and the second edge pad (212). In the first direction (Y), the harpoon structure (3), the first fine gate (41) and the second fine gate (42) are disposed between the first edge pad (211) and the first edge (11), and the harpoon structure (3), the first fine gate (41) and the second fine gate (42) are disposed between the second edge pad (212) and the second edge (12).

5. The battery cell according to claim 1, characterized in that, The body (1) includes a first edge (11) and a second edge (12) arranged along the first direction (Y), and the edge pad (21) includes a first edge pad (211) and a second edge pad (212) arranged along the first direction (Y). In the first direction (Y), the first edge pad (211) is located between the first edge (11) and the second edge pad (212). In the first direction (Y), the harpoon structure (3) is provided between the first edge pad (211) and the first edge (11), and between the second edge pad (212) and the second edge (12); In the first direction (Y), the first fine gate (41) and the second fine gate (42) are located between the first edge pad (211) and the first edge (11); The fine gate (4) further includes a fourth fine gate (44), which is located between the second edge pad (212) and the second edge (12) in the first direction (Y). The fourth fine gate (44) is connected to the harpoon structure (3) and extends through the harpoon gap (33) along the second direction (X).

6. The battery cell according to claim 5, characterized in that, The fine grid (4) further includes a fifth fine grid (45), which is located between the fourth fine grid (44) and the second edge (12) in the first direction (Y); The fifth fine grid (45) is connected to the harpoon structure (3), and the fifth fine grid (45) is disconnected at the harpoon gap (33).

7. The battery cell according to any one of claims 1 to 6, characterized in that, The central pad (22) includes a main pad (221) and a secondary pad (222). A plurality of the main pads (221) are arranged along the first direction (Y), and at least two secondary pads (222) are included between two adjacent main pads (221). In the thickness direction of the battery cell, the projected area of ​​the main pad (221) is larger than the projected area of ​​the sub-pad (222).

8. The battery cell according to claim 7, characterized in that, In the first direction (Y), at least three of the sub-pads (222) are included between the edge pad (21) and the adjacent main pad (221).

9. The battery cell according to claim 7, characterized in that, The outline shape of the main pad (221) is circular or rectangular; The outline shape of the sub-pad (222) is T-shaped, I-shaped or Z-shaped.

10. The battery cell according to any one of claims 1 to 6, characterized in that, In the first direction (Y), the number of fine gates (4) between two adjacent pads (2) is 0, or at least one fine gate (4) is included between two adjacent pads (2); The pads (2) and the fine gates (4) are arranged periodically in the first direction (Y).

11. The battery cell according to claim 10, characterized in that, In the first direction (Y), the number of fine gates (4) between two adjacent pads (2) is 0; The central pad (22) includes a main pad (221) and a secondary pad (222). In the thickness direction of the battery cell, the projected area of ​​the main pad (221) is larger than the projected area of ​​the secondary pad (222). The fine gate (4) includes a main fine gate (48) and a secondary fine gate (49). The end of the main fine gate (48) contacts the main pad (221), and the end of the secondary fine gate (49) contacts the secondary pad (222). In the first direction (Y), the distance between the main fine gate (48) and the adjacent secondary fine gate (49) is L1, and the distance between two adjacent secondary fine gates (49) is L2, 0.3≤L1 / L2≤7.

12. The battery cell according to claim 11, characterized in that, 0.5mm≤L1≤2mm, 0.3mm≤L2≤1.5mm, and L2<L1.

13. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell is a gridless battery cell, and the pad (2) is directly connected to the grid (4).

14. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell also includes a main grid (5) extending along the first direction (Y), the fine grid (4) being connected to the main grid (5), and at least a portion of the pads (2) being located on the main grid (5); The plurality of main gates (5) are arranged at intervals along the second direction (X), and the number of main gates (5) in the second direction (X) is N4, where 5≤N4≤24.

15. The battery cell according to claim 14, characterized in that, The pads (2) arranged along the first direction (Y) form a pad column (23), and multiple pad columns (23) are arranged along the second direction (X); In the second direction (X), the number of main gates (5) is the same as the number of pad rows (23); Alternatively, in the second direction (X), the number of main gates (5) is less than the number of pad columns (23), and at least one pad column (23) is included between two adjacent main gates (5).

16. The battery cell according to any one of claims 1 to 6, characterized in that, The battery cell also includes a main grid (5) extending along the first direction (Y), the fine grid (4) being connected to the main grid (5), and at least a portion of the pads (2) being located on the main grid (5); The number of main gates (5) in the first direction (Y) is 1; Alternatively, multiple main gates (5) may be arranged at intervals along the first direction (Y).

17. A photovoltaic module, characterized in that, The photovoltaic module includes a cover plate (10), an encapsulation layer (20), and a battery layer (30), wherein the battery layer (30) includes a plurality of battery cells according to any one of claims 1 to 16.

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